Move Stats, histograms, and field trial into a metrics subdirectory of base and

put them in the base namespace.

TEST=it compiles
BUG=none

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@62510 0039d316-1c4b-4281-b951-d872f2087c98

237 files changed, 938 insertions, 826 deletions

diff --git a/app/sql/diagnostic_error_delegate.h b/app/sql/diagnostic_error_delegate.h
index 1c2d6e9..713c4aa 100644
--- a/app/sql/diagnostic_error_delegate.h
+++ b/app/sql/diagnostic_error_delegate.h
@@ -7,8 +7,8 @@
 #pragma once
 
 #include "app/sql/connection.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 
 namespace sql {
 
diff --git a/base/base.gyp b/base/base.gyp
index 2f541ee..d6245ca 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -81,13 +81,11 @@
         'event_trace_consumer_win_unittest.cc',
         'event_trace_controller_win_unittest.cc',
         'event_trace_provider_win_unittest.cc',
-        'field_trial_unittest.cc',
         'file_descriptor_shuffle_unittest.cc',
         'file_path_unittest.cc',
         'file_util_unittest.cc',
         'file_version_info_unittest.cc',
         'gmock_unittest.cc',
-        'histogram_unittest.cc',
         'hmac_unittest.cc',
         'id_map_unittest.cc',
         'i18n/char_iterator_unittest.cc',
@@ -108,6 +106,9 @@
         'message_loop_proxy_impl_unittest.cc',
         'message_loop_unittest.cc',
         'message_pump_glib_unittest.cc',
+        'metrics/field_trial_unittest.cc',
+        'metrics/histogram_unittest.cc',
+        'metrics/stats_table_unittest.cc',
         'non_thread_safe_unittest.cc',
         'object_watcher_unittest.cc',
         'observer_list_unittest.cc',
@@ -135,7 +136,6 @@
         'simple_thread_unittest.cc',
         'singleton_unittest.cc',
         'stack_container_unittest.cc',
-        'stats_table_unittest.cc',
         'string_number_conversions_unittest.cc',
         'string_piece_unittest.cc',
         'string_split_unittest.cc',
diff --git a/base/base.gypi b/base/base.gypi
index bd15b00..9329ccb 100644
--- a/base/base.gypi
+++ b/base/base.gypi
@@ -95,8 +95,6 @@
           'gtk_util.cc',
           'gtk_util.h',
           'hash_tables.h',
-          'histogram.cc',
-          'histogram.h',
           'iat_patch.cc',
           'iat_patch.h',
           'id_map.h',
@@ -138,6 +136,12 @@
           'message_pump_default.h',
           'message_pump_win.cc',
           'message_pump_win.h',
+          'metrics/histogram.cc',
+          'metrics/histogram.h',
+          'metrics/stats_counters.cc',
+          'metrics/stats_counters.h',
+          'metrics/stats_table.cc',
+          'metrics/stats_table.h',
           'mime_util.h',
           'mime_util_xdg.cc',
           'move.h',
@@ -223,10 +227,6 @@
           'singleton.h',
           'spin_wait.h',
           'stack_container.h',
-          'stats_counters.cc',
-          'stats_counters.h',
-          'stats_table.cc',
-          'stats_table.h',
           'stl_util-inl.h',
           'string_number_conversions.cc',
           'string_number_conversions.h',
@@ -429,8 +429,6 @@
           'event_recorder.cc',
           'event_recorder.h',
           'event_recorder_stubs.cc',
-          'field_trial.cc',
-          'field_trial.h',
           'file_descriptor_shuffle.cc',
           'file_descriptor_shuffle.h',
           'hmac.h',
@@ -449,6 +447,8 @@
           'message_pump_libevent.h',
           'message_pump_mac.h',
           'message_pump_mac.mm',
+          'metrics/field_trial.cc',
+          'metrics/field_trial.h',
           'nsimage_cache_mac.h',
           'nsimage_cache_mac.mm',
           'nss_util.cc',
diff --git a/base/data_pack.cc b/base/data_pack.cc
index 29ecf98..e01318f 100644
--- a/base/data_pack.cc
+++ b/base/data_pack.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -7,8 +7,8 @@
 #include <errno.h>
 
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/ref_counted_memory.h"
 #include "base/string_piece.h"
 
diff --git a/base/file_util_win.cc b/base/file_util_win.cc
index 876b89d..dec4be6 100644
--- a/base/file_util_win.cc
+++ b/base/file_util_win.cc
@@ -13,8 +13,8 @@
 #include <string>
 
 #include "base/file_path.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/pe_image.h"
 #include "base/scoped_comptr_win.h"
 #include "base/scoped_handle.h"
diff --git a/base/message_loop.cc b/base/message_loop.cc
index 56d1418..8f6c997b 100644
--- a/base/message_loop.cc
+++ b/base/message_loop.cc
@@ -7,10 +7,10 @@
 #include <algorithm>
 
 #include "base/compiler_specific.h"
-#include "base/histogram.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/message_pump_default.h"
+#include "base/metrics/histogram.h"
 #include "base/thread_local.h"
 
 #if defined(OS_MACOSX)
@@ -60,7 +60,7 @@ const int kNumberOfDistinctMessagesDisplayed = 1100;
 // in the pair (i.e., the quoted string) when printing out a histogram.
 #define VALUE_TO_NUMBER_AND_NAME(name) {name, #name},
 
-const LinearHistogram::DescriptionPair event_descriptions_[] = {
+const base::LinearHistogram::DescriptionPair event_descriptions_[] = {
   // Provide some pretty print capability in our histogram for our internal
   // messages.
 
@@ -617,9 +617,10 @@ void MessageLoop::EnableHistogrammer(bool enable) {
 
 void MessageLoop::StartHistogrammer() {
   if (enable_histogrammer_ && !message_histogram_.get()
-      && StatisticsRecorder::WasStarted()) {
+      && base::StatisticsRecorder::WasStarted()) {
     DCHECK(!thread_name_.empty());
-    message_histogram_ = LinearHistogram::FactoryGet("MsgLoop:" + thread_name_,
+    message_histogram_ = base::LinearHistogram::FactoryGet(
+        "MsgLoop:" + thread_name_,
         kLeastNonZeroMessageId, kMaxMessageId,
         kNumberOfDistinctMessagesDisplayed,
         message_histogram_->kHexRangePrintingFlag);
diff --git a/base/message_loop.h b/base/message_loop.h
index 363c5d0..94e0096 100644
--- a/base/message_loop.h
+++ b/base/message_loop.h
@@ -27,7 +27,9 @@
 #endif
 #endif
 
+namespace base {
 class Histogram;
+}
 
 // A MessageLoop is used to process events for a particular thread.  There is
 // at most one MessageLoop instance per thread.
@@ -457,7 +459,7 @@ class MessageLoop : public base::MessagePump::Delegate {
 
   std::string thread_name_;
   // A profiling histogram showing the counts of various messages and events.
-  scoped_refptr<Histogram> message_histogram_;
+  scoped_refptr<base::Histogram> message_histogram_;
 
   // A null terminated list which creates an incoming_queue of tasks that are
   // aquired under a mutex for processing on this instance's thread. These tasks
diff --git a/base/message_pump_win.cc b/base/message_pump_win.cc
index fc4b2e4..d0afd51 100644
--- a/base/message_pump_win.cc
+++ b/base/message_pump_win.cc
@@ -6,9 +6,7 @@
 
 #include <math.h>
 
-#include "base/histogram.h"
-
-using base::Time;
+#include "base/metrics/histogram.h"
 
 namespace base {
 
diff --git a/base/field_trial.cc b/base/metrics/field_trial.cc
index a3e6ac6..63d9ed5 100644
--- a/base/field_trial.cc
+++ b/base/metrics/field_trial.cc
@@ -2,13 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/field_trial.h"
+#include "base/metrics/field_trial.h"
 
 #include "base/logging.h"
 #include "base/rand_util.h"
 #include "base/stringprintf.h"
 
-using base::TimeTicks;
+namespace base {
 
 // static
 const int FieldTrial::kNotParticipating = -1;
@@ -190,3 +190,4 @@ bool FieldTrialList::StringAugmentsState(const std::string& prior_state) {
   return true;
 }
 
+}  // namespace base
diff --git a/base/field_trial.h b/base/metrics/field_trial.h
index deee838..348a1a7 100644
--- a/base/field_trial.h
+++ b/base/metrics/field_trial.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -59,8 +59,8 @@
 
 //------------------------------------------------------------------------------
 
-#ifndef BASE_FIELD_TRIAL_H_
-#define BASE_FIELD_TRIAL_H_
+#ifndef BASE_METRICS_FIELD_TRIAL_H_
+#define BASE_METRICS_FIELD_TRIAL_H_
 #pragma once
 
 #include <map>
@@ -70,8 +70,9 @@
 #include "base/ref_counted.h"
 #include "base/time.h"
 
+namespace base {
 
-class FieldTrial : public base::RefCounted<FieldTrial> {
+class FieldTrial : public RefCounted<FieldTrial> {
  public:
   typedef int Probability;  // Probability type for being selected in a trial.
 
@@ -117,7 +118,7 @@ class FieldTrial : public base::RefCounted<FieldTrial> {
                               const std::string& trial_name);
 
  private:
-  friend class base::RefCounted<FieldTrial>;
+  friend class RefCounted<FieldTrial>;
 
   virtual ~FieldTrial();
 
@@ -198,11 +199,11 @@ class FieldTrialList {
   // of the application.  In some experiments it may be useful to discount
   // data that is gathered before the application has reached sufficient
   // stability (example: most DLL have loaded, etc.)
-  static base::TimeTicks application_start_time() {
+  static TimeTicks application_start_time() {
     if (global_)
       return global_->application_start_time_;
     // For testing purposes only, or when we don't yet have a start time.
-    return base::TimeTicks::Now();
+    return TimeTicks::Now();
   }
 
  private:
@@ -222,7 +223,7 @@ class FieldTrialList {
   // A helper value made availabel to users, that shows when the FieldTrialList
   // was initialized.  Note that this is a singleton instance, and hence is a
   // good approximation to the start of the process.
-  base::TimeTicks application_start_time_;
+  TimeTicks application_start_time_;
 
   // Lock for access to registered_.
   Lock lock_;
@@ -231,5 +232,7 @@ class FieldTrialList {
   DISALLOW_COPY_AND_ASSIGN(FieldTrialList);
 };
 
-#endif  // BASE_FIELD_TRIAL_H_
+}  // namespace base
+
+#endif  // BASE_METRICS_FIELD_TRIAL_H_
 
diff --git a/base/field_trial_unittest.cc b/base/metrics/field_trial_unittest.cc
index 94eb7fc..aea8e85 100644
--- a/base/field_trial_unittest.cc
+++ b/base/metrics/field_trial_unittest.cc
@@ -1,14 +1,16 @@
-// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Test of FieldTrial class
 
-#include "base/field_trial.h"
+#include "base/metrics/field_trial.h"
 
 #include "base/stringprintf.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+namespace base {
+
 class FieldTrialTest : public testing::Test {
  public:
   FieldTrialTest() : trial_list_() { }
@@ -76,7 +78,7 @@ TEST_F(FieldTrialTest, RemainingProbability) {
   scoped_refptr<FieldTrial> trial;
   int counter = 0;
   do {
-    std::string name = base::StringPrintf("trial%d", ++counter);
+    std::string name = StringPrintf("trial%d", ++counter);
     trial = new FieldTrial(name, 10);
     trial->AppendGroup(loser, 5);  // 50% chance of not being chosen.
   } while (trial->group() != FieldTrial::kNotParticipating);
@@ -227,3 +229,5 @@ TEST_F(FieldTrialTest, MakeName) {
   EXPECT_EQ("Histogram_Winner",
             FieldTrial::MakeName("Histogram", "Field Trial"));
 }
+
+}  // namespace base
diff --git a/base/histogram.cc b/base/metrics/histogram.cc
index e045d81..9746e9c 100644
--- a/base/histogram.cc
+++ b/base/metrics/histogram.cc
@@ -7,7 +7,7 @@
 // vector of numbers corresponding to each of the aggregating buckets).
 // See header file for details and examples.
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 
 #include <math.h>
 
@@ -19,7 +19,7 @@
 #include "base/pickle.h"
 #include "base/stringprintf.h"
 
-using base::TimeDelta;
+namespace base {
 
 typedef Histogram::Count Count;
 
@@ -45,8 +45,10 @@ scoped_refptr<Histogram> Histogram::FactoryGet(const std::string& name,
 }
 
 scoped_refptr<Histogram> Histogram::FactoryTimeGet(const std::string& name,
-    base::TimeDelta minimum, base::TimeDelta maximum, size_t bucket_count,
-    Flags flags) {
+                                                   TimeDelta minimum,
+                                                   TimeDelta maximum,
+                                                   size_t bucket_count,
+                                                   Flags flags) {
   return FactoryGet(name, minimum.InMilliseconds(), maximum.InMilliseconds(),
                     bucket_count, flags);
 }
@@ -304,14 +306,15 @@ void Histogram::SnapshotSample(SampleSet* sample) const {
   *sample = sample_;
 }
 
-bool Histogram::HasConstructorArguments(Sample minimum, Sample maximum,
+bool Histogram::HasConstructorArguments(Sample minimum,
+                                        Sample maximum,
                                         size_t bucket_count) {
   return ((minimum == declared_min_) && (maximum == declared_max_) &&
           (bucket_count == bucket_count_));
 }
 
-bool Histogram::HasConstructorTimeDeltaArguments(base::TimeDelta minimum,
-                                                 base::TimeDelta maximum,
+bool Histogram::HasConstructorTimeDeltaArguments(TimeDelta minimum,
+                                                 TimeDelta maximum,
                                                  size_t bucket_count) {
   return ((minimum.InMilliseconds() == declared_min_) &&
           (maximum.InMilliseconds() == declared_max_) &&
@@ -342,10 +345,10 @@ double Histogram::GetPeakBucketSize(const SampleSet& snapshot) const {
 void Histogram::WriteAsciiHeader(const SampleSet& snapshot,
                                  Count sample_count,
                                  std::string* output) const {
-  base::StringAppendF(output,
-                      "Histogram: %s recorded %d samples",
-                      histogram_name().c_str(),
-                      sample_count);
+  StringAppendF(output,
+                "Histogram: %s recorded %d samples",
+                histogram_name().c_str(),
+                sample_count);
   if (0 == sample_count) {
     DCHECK_EQ(snapshot.sum(), 0);
   } else {
@@ -354,13 +357,12 @@ void Histogram::WriteAsciiHeader(const SampleSet& snapshot,
                       - average * average;
     double standard_deviation = sqrt(variance);
 
-    base::StringAppendF(output,
-                        ", average = %.1f, standard deviation = %.1f",
-                        average, standard_deviation);
+    StringAppendF(output,
+                  ", average = %.1f, standard deviation = %.1f",
+                  average, standard_deviation);
   }
-  if (flags_ & ~kHexRangePrintingFlag )
-    base::StringAppendF(output, " (flags = 0x%x)",
-                        flags_ & ~kHexRangePrintingFlag);
+  if (flags_ & ~kHexRangePrintingFlag)
+    StringAppendF(output, " (flags = 0x%x)", flags_ & ~kHexRangePrintingFlag);
 }
 
 void Histogram::WriteAsciiBucketContext(const int64 past,
@@ -372,22 +374,22 @@ void Histogram::WriteAsciiBucketContext(const int64 past,
   WriteAsciiBucketValue(current, scaled_sum, output);
   if (0 < i) {
     double percentage = past / scaled_sum;
-    base::StringAppendF(output, " {%3.1f%%}", percentage);
+    StringAppendF(output, " {%3.1f%%}", percentage);
   }
 }
 
 const std::string Histogram::GetAsciiBucketRange(size_t i) const {
   std::string result;
   if (kHexRangePrintingFlag & flags_)
-    base::StringAppendF(&result, "%#x", ranges(i));
+    StringAppendF(&result, "%#x", ranges(i));
   else
-    base::StringAppendF(&result, "%d", ranges(i));
+    StringAppendF(&result, "%d", ranges(i));
   return result;
 }
 
 void Histogram::WriteAsciiBucketValue(Count current, double scaled_sum,
                                       std::string* output) const {
-  base::StringAppendF(output, " (%d = %3.1f%%)", current, current/scaled_sum);
+  StringAppendF(output, " (%d = %3.1f%%)", current, current/scaled_sum);
 }
 
 void Histogram::WriteAsciiBucketGraph(double current_size, double max_size,
@@ -600,9 +602,11 @@ bool Histogram::SampleSet::Deserialize(void** iter, const Pickle& pickle) {
 // buckets.
 //------------------------------------------------------------------------------
 
-scoped_refptr<Histogram> LinearHistogram::FactoryGet(
-    const std::string& name, Sample minimum, Sample maximum,
-    size_t bucket_count, Flags flags) {
+scoped_refptr<Histogram> LinearHistogram::FactoryGet(const std::string& name,
+                                                     Sample minimum,
+                                                     Sample maximum,
+                                                     size_t bucket_count,
+                                                     Flags flags) {
   scoped_refptr<Histogram> histogram(NULL);
 
   if (minimum <= 0)
@@ -622,8 +626,11 @@ scoped_refptr<Histogram> LinearHistogram::FactoryGet(
 }
 
 scoped_refptr<Histogram> LinearHistogram::FactoryTimeGet(
-    const std::string& name, base::TimeDelta minimum, base::TimeDelta maximum,
-    size_t bucket_count, Flags flags) {
+    const std::string& name,
+    TimeDelta minimum,
+    TimeDelta maximum,
+    size_t bucket_count,
+    Flags flags) {
   return FactoryGet(name, minimum.InMilliseconds(), maximum.InMilliseconds(),
                     bucket_count, flags);
 }
@@ -631,15 +638,19 @@ scoped_refptr<Histogram> LinearHistogram::FactoryTimeGet(
 LinearHistogram::~LinearHistogram() {
 }
 
-LinearHistogram::LinearHistogram(const std::string& name, Sample minimum,
-    Sample maximum, size_t bucket_count)
+LinearHistogram::LinearHistogram(const std::string& name,
+                                 Sample minimum,
+                                 Sample maximum,
+                                 size_t bucket_count)
     : Histogram(name, minimum >= 1 ? minimum : 1, maximum, bucket_count) {
   InitializeBucketRange();
   DCHECK(ValidateBucketRanges());
 }
 
 LinearHistogram::LinearHistogram(const std::string& name,
-    TimeDelta minimum, TimeDelta maximum, size_t bucket_count)
+                                 TimeDelta minimum,
+                                 TimeDelta maximum,
+                                 size_t bucket_count)
     : Histogram(name, minimum >= TimeDelta::FromMilliseconds(1) ?
                                  minimum : TimeDelta::FromMilliseconds(1),
                 maximum, bucket_count) {
@@ -727,7 +738,8 @@ BooleanHistogram::BooleanHistogram(const std::string& name)
 //------------------------------------------------------------------------------
 
 scoped_refptr<Histogram> CustomHistogram::FactoryGet(
-    const std::string& name, const std::vector<int>& custom_ranges,
+    const std::string& name,
+    const std::vector<int>& custom_ranges,
     Flags flags) {
   scoped_refptr<Histogram> histogram(NULL);
 
@@ -761,7 +773,7 @@ Histogram::ClassType CustomHistogram::histogram_type() const {
 }
 
 CustomHistogram::CustomHistogram(const std::string& name,
-    const std::vector<int>& custom_ranges)
+                                 const std::vector<int>& custom_ranges)
     : Histogram(name, custom_ranges[1], custom_ranges.back(),
                 custom_ranges.size()) {
   DCHECK_GT(custom_ranges.size(), 1u);
@@ -774,9 +786,8 @@ CustomHistogram::CustomHistogram(const std::string& name,
 
 void CustomHistogram::InitializeBucketRange() {
   DCHECK(ranges_vector_->size() <= bucket_count());
-  for (size_t index = 0; index < ranges_vector_->size(); ++index) {
+  for (size_t index = 0; index < ranges_vector_->size(); ++index)
     SetBucketRange(index, (*ranges_vector_)[index]);
-  }
 }
 
 double CustomHistogram::GetBucketSize(Count current, size_t i) const {
@@ -862,12 +873,10 @@ void StatisticsRecorder::WriteGraph(const std::string& query,
                                     std::string* output) {
   if (!histograms_)
     return;
-  if (query.length()) {
-    base::StringAppendF(output, "Collections of histograms for %s\n",
-                        query.c_str());
-  } else {
+  if (query.length())
+    StringAppendF(output, "Collections of histograms for %s\n", query.c_str());
+  else
     output->append("Collections of all histograms\n");
-  }
 
   Histograms snapshot;
   GetSnapshot(query, &snapshot);
@@ -922,3 +931,5 @@ StatisticsRecorder::HistogramMap* StatisticsRecorder::histograms_ = NULL;
 Lock* StatisticsRecorder::lock_ = NULL;
 // static
 bool StatisticsRecorder::dump_on_exit_ = false;
+
+}  // namespace base
diff --git a/base/histogram.h b/base/metrics/histogram.h
index 0287d37..20f67c2 100644
--- a/base/histogram.h
+++ b/base/metrics/histogram.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -28,8 +28,8 @@
 // at the low end of the histogram scale, but allows the histogram to cover a
 // gigantic range with the addition of very few buckets.
 
-#ifndef BASE_HISTOGRAM_H_
-#define BASE_HISTOGRAM_H_
+#ifndef BASE_METRICS_HISTOGRAM_H_
+#define BASE_METRICS_HISTOGRAM_H_
 #pragma once
 
 #include <map>
@@ -41,6 +41,9 @@
 #include "base/time.h"
 
 class Lock;
+class Pickle;
+
+namespace base {
 
 //------------------------------------------------------------------------------
 // Provide easy general purpose histogram in a macro, just like stats counters.
@@ -60,8 +63,9 @@ class Lock;
     name, sample, 1, 10000, 50)
 
 #define HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, bucket_count) do { \
-    static scoped_refptr<Histogram> counter = Histogram::FactoryGet( \
-        name, min, max, bucket_count, Histogram::kNoFlags); \
+    static scoped_refptr<base::Histogram> counter = \
+        base::Histogram::FactoryGet(name, min, max, bucket_count, \
+                                    base::Histogram::kNoFlags); \
     DCHECK_EQ(name, counter->histogram_name()); \
     if (counter.get()) counter->Add(sample); \
   } while (0)
@@ -72,16 +76,18 @@ class Lock;
 // For folks that need real specific times, use this to select a precise range
 // of times you want plotted, and the number of buckets you want used.
 #define HISTOGRAM_CUSTOM_TIMES(name, sample, min, max, bucket_count) do { \
-    static scoped_refptr<Histogram> counter = Histogram::FactoryTimeGet( \
-        name, min, max, bucket_count, Histogram::kNoFlags); \
+    static scoped_refptr<base::Histogram> counter = \
+        base::Histogram::FactoryTimeGet(name, min, max, bucket_count, \
+                                        base::Histogram::kNoFlags); \
     DCHECK_EQ(name, counter->histogram_name()); \
     if (counter.get()) counter->AddTime(sample); \
   } while (0)
 
 // DO NOT USE THIS.  It is being phased out, in favor of HISTOGRAM_CUSTOM_TIMES.
 #define HISTOGRAM_CLIPPED_TIMES(name, sample, min, max, bucket_count) do { \
-    static scoped_refptr<Histogram> counter = Histogram::FactoryTimeGet( \
-        name, min, max, bucket_count, Histogram::kNoFlags); \
+    static scoped_refptr<base::Histogram> counter = \
+        base::Histogram::FactoryTimeGet(name, min, max, bucket_count, \
+                                        base::Histogram::kNoFlags); \
     DCHECK_EQ(name, counter->histogram_name()); \
     if ((sample) < (max) && counter.get()) counter->AddTime(sample); \
   } while (0)
@@ -90,15 +96,18 @@ class Lock;
 // less than boundary_value.
 
 #define HISTOGRAM_ENUMERATION(name, sample, boundary_value) do { \
-    static scoped_refptr<Histogram> counter = LinearHistogram::FactoryGet( \
-        name, 1, boundary_value, boundary_value + 1, Histogram::kNoFlags); \
+    static scoped_refptr<base::Histogram> counter = \
+        base::LinearHistogram::FactoryGet(name, 1, boundary_value, \
+                                          boundary_value + 1, \
+                                          base::Histogram::kNoFlags); \
     DCHECK_EQ(name, counter->histogram_name()); \
     if (counter.get()) counter->Add(sample); \
   } while (0)
 
 #define HISTOGRAM_CUSTOM_ENUMERATION(name, sample, custom_ranges) do { \
-    static scoped_refptr<Histogram> counter = CustomHistogram::FactoryGet( \
-        name, custom_ranges, Histogram::kNoFlags); \
+    static scoped_refptr<base::Histogram> counter = \
+        base::CustomHistogram::FactoryGet(name, custom_ranges, \
+                                          base::Histogram::kNoFlags); \
     DCHECK_EQ(name, counter->histogram_name()); \
     if (counter.get()) counter->Add(sample); \
   } while (0)
@@ -160,16 +169,18 @@ class Lock;
     base::TimeDelta::FromHours(1), 50)
 
 #define UMA_HISTOGRAM_CUSTOM_TIMES(name, sample, min, max, bucket_count) do { \
-    static scoped_refptr<Histogram> counter = Histogram::FactoryTimeGet( \
-        name, min, max, bucket_count, Histogram::kUmaTargetedHistogramFlag); \
+    static scoped_refptr<base::Histogram> counter = \
+        base::Histogram::FactoryTimeGet(name, min, max, bucket_count, \
+            base::Histogram::kUmaTargetedHistogramFlag); \
     DCHECK_EQ(name, counter->histogram_name()); \
     if (counter.get()) counter->AddTime(sample); \
   } while (0)
 
 // DO NOT USE THIS.  It is being phased out, in favor of HISTOGRAM_CUSTOM_TIMES.
 #define UMA_HISTOGRAM_CLIPPED_TIMES(name, sample, min, max, bucket_count) do { \
-    static scoped_refptr<Histogram> counter = Histogram::FactoryTimeGet( \
-        name, min, max, bucket_count, Histogram::kUmaTargetedHistogramFlag); \
+    static scoped_refptr<base::Histogram> counter = \
+        base::Histogram::FactoryTimeGet(name, min, max, bucket_count, \
+            base::Histogram::kUmaTargetedHistogramFlag); \
     DCHECK_EQ(name, counter->histogram_name()); \
     if ((sample) < (max) && counter.get()) counter->AddTime(sample); \
   } while (0)
@@ -184,8 +195,9 @@ class Lock;
     name, sample, 1, 10000, 50)
 
 #define UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, bucket_count) do { \
-    static scoped_refptr<Histogram> counter = Histogram::FactoryGet( \
-        name, min, max, bucket_count, Histogram::kUmaTargetedHistogramFlag); \
+    static scoped_refptr<base::Histogram> counter = \
+       base::Histogram::FactoryGet(name, min, max, bucket_count, \
+           base::Histogram::kUmaTargetedHistogramFlag); \
     DCHECK_EQ(name, counter->histogram_name()); \
     if (counter.get()) counter->Add(sample); \
   } while (0)
@@ -200,16 +212,17 @@ class Lock;
     UMA_HISTOGRAM_ENUMERATION(name, under_one_hundred, 101)
 
 #define UMA_HISTOGRAM_ENUMERATION(name, sample, boundary_value) do { \
-    static scoped_refptr<Histogram> counter = LinearHistogram::FactoryGet( \
-        name, 1, boundary_value, boundary_value + 1, \
-        Histogram::kUmaTargetedHistogramFlag); \
+    static scoped_refptr<base::Histogram> counter = \
+        base::LinearHistogram::FactoryGet(name, 1, boundary_value, \
+            boundary_value + 1, base::Histogram::kUmaTargetedHistogramFlag); \
     DCHECK_EQ(name, counter->histogram_name()); \
     if (counter.get()) counter->Add(sample); \
   } while (0)
 
 #define UMA_HISTOGRAM_CUSTOM_ENUMERATION(name, sample, custom_ranges) do { \
-    static scoped_refptr<Histogram> counter = CustomHistogram::FactoryGet( \
-        name, custom_ranges, Histogram::kUmaTargetedHistogramFlag); \
+    static scoped_refptr<base::Histogram> counter = \
+        base::CustomHistogram::FactoryGet(name, custom_ranges, \
+            base::Histogram::kUmaTargetedHistogramFlag); \
     DCHECK_EQ(name, counter->histogram_name()); \
     if (counter.get()) counter->Add(sample); \
   } while (0)
@@ -220,7 +233,6 @@ class BooleanHistogram;
 class CustomHistogram;
 class Histogram;
 class LinearHistogram;
-class Pickle;
 
 class Histogram : public base::RefCountedThreadSafe<Histogram> {
  public:
@@ -319,7 +331,7 @@ class Histogram : public base::RefCountedThreadSafe<Histogram> {
   virtual void AddBoolean(bool value);
 
   // Accept a TimeDelta to increment.
-  void AddTime(base::TimeDelta time) {
+  void AddTime(TimeDelta time) {
     Add(static_cast<int>(time.InMilliseconds()));
   }
 
@@ -371,16 +383,16 @@ class Histogram : public base::RefCountedThreadSafe<Histogram> {
   virtual bool HasConstructorArguments(Sample minimum, Sample maximum,
                                        size_t bucket_count);
 
-  virtual bool HasConstructorTimeDeltaArguments(base::TimeDelta minimum,
-                                                base::TimeDelta maximum,
+  virtual bool HasConstructorTimeDeltaArguments(TimeDelta minimum,
+                                                TimeDelta maximum,
                                                 size_t bucket_count);
 
  protected:
   friend class base::RefCountedThreadSafe<Histogram>;
   Histogram(const std::string& name, Sample minimum,
             Sample maximum, size_t bucket_count);
-  Histogram(const std::string& name, base::TimeDelta minimum,
-            base::TimeDelta maximum, size_t bucket_count);
+  Histogram(const std::string& name, TimeDelta minimum,
+            TimeDelta maximum, size_t bucket_count);
 
   virtual ~Histogram();
 
@@ -489,7 +501,7 @@ class LinearHistogram : public Histogram {
   static scoped_refptr<Histogram> FactoryGet(const std::string& name,
       Sample minimum, Sample maximum, size_t bucket_count, Flags flags);
   static scoped_refptr<Histogram> FactoryTimeGet(const std::string& name,
-      base::TimeDelta minimum, base::TimeDelta maximum, size_t bucket_count,
+      TimeDelta minimum, TimeDelta maximum, size_t bucket_count,
       Flags flags);
 
   virtual ~LinearHistogram();
@@ -498,8 +510,8 @@ class LinearHistogram : public Histogram {
   LinearHistogram(const std::string& name, Sample minimum,
                   Sample maximum, size_t bucket_count);
 
-  LinearHistogram(const std::string& name, base::TimeDelta minimum,
-                  base::TimeDelta maximum, size_t bucket_count);
+  LinearHistogram(const std::string& name, TimeDelta minimum,
+                  TimeDelta maximum, size_t bucket_count);
 
   // Initialize ranges_ mapping.
   virtual void InitializeBucketRange();
@@ -626,4 +638,6 @@ class StatisticsRecorder {
   DISALLOW_COPY_AND_ASSIGN(StatisticsRecorder);
 };
 
-#endif  // BASE_HISTOGRAM_H_
+}  // namespace base
+
+#endif  // BASE_METRICS_HISTOGRAM_H_
diff --git a/base/histogram_unittest.cc b/base/metrics/histogram_unittest.cc
index 4637a5f..e7e3983 100644
--- a/base/histogram_unittest.cc
+++ b/base/metrics/histogram_unittest.cc
@@ -4,12 +4,11 @@
 
 // Test of Histogram class
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-using base::TimeDelta;
-
+namespace base {
 namespace {
 
 class HistogramTest : public testing::Test {
@@ -308,5 +307,5 @@ TEST(HistogramTest, BucketPlacementTest) {
     EXPECT_EQ(i + 1, sample.counts(i));
 }
 
-
 }  // namespace
+}  // namespace base
diff --git a/base/stats_counters.cc b/base/metrics/stats_counters.cc
index 345e1d6..958f048 100644
--- a/base/stats_counters.cc
+++ b/base/metrics/stats_counters.cc
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
+
+namespace base {
 
 StatsCounter::StatsCounter(const std::string& name)
     : counter_id_(-1) {
@@ -69,15 +71,15 @@ StatsCounterTimer::~StatsCounterTimer() {
 void StatsCounterTimer::Start() {
   if (!Enabled())
     return;
-  start_time_ = base::TimeTicks::Now();
-  stop_time_ = base::TimeTicks();
+  start_time_ = TimeTicks::Now();
+  stop_time_ = TimeTicks();
 }
 
 // Stop the timer and record the results.
 void StatsCounterTimer::Stop() {
   if (!Enabled() || !Running())
     return;
-  stop_time_ = base::TimeTicks::Now();
+  stop_time_ = TimeTicks::Now();
   Record();
 }
 
@@ -87,7 +89,7 @@ bool StatsCounterTimer::Running() {
 }
 
 // Accept a TimeDelta to increment.
-void StatsCounterTimer::AddTime(base::TimeDelta time) {
+void StatsCounterTimer::AddTime(TimeDelta time) {
   Add(static_cast<int>(time.InMilliseconds()));
 }
 
@@ -96,10 +98,10 @@ void StatsCounterTimer::Record() {
 }
 
 
-StatsRate::StatsRate(const char* name)
+StatsRate::StatsRate(const std::string& name)
     : StatsCounterTimer(name),
       counter_(name),
-      largest_add_(std::string(" ").append(name).append("MAX").c_str()) {
+      largest_add_(std::string(" ").append(name).append("MAX")) {
 }
 
 StatsRate::~StatsRate() {
@@ -111,3 +113,5 @@ void StatsRate::Add(int value) {
   if (value > largest_add_.value())
     largest_add_.Set(value);
 }
+
+}  // namespace base
diff --git a/base/stats_counters.h b/base/metrics/stats_counters.h
index defb9ee..2de2b73 100644
--- a/base/stats_counters.h
+++ b/base/metrics/stats_counters.h
@@ -1,16 +1,18 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-
-#ifndef BASE_STATS_COUNTERS_H__
-#define BASE_STATS_COUNTERS_H__
+#ifndef BASE_METRICS_STATS_COUNTERS_H_
+#define BASE_METRICS_STATS_COUNTERS_H_
 #pragma once
 
 #include <string>
-#include "base/stats_table.h"
+
+#include "base/metrics/stats_table.h"
 #include "base/time.h"
 
+namespace base {
+
 // StatsCounters are dynamically created values which can be tracked in
 // the StatsTable.  They are designed to be lightweight to create and
 // easy to use.
@@ -44,14 +46,14 @@
 //------------------------------------------------------------------------------
 // First provide generic macros, which exist in production as well as debug.
 #define STATS_COUNTER(name, delta) do { \
-  static StatsCounter counter(name); \
+  static base::StatsCounter counter(name); \
   counter.Add(delta); \
 } while (0)
 
 #define SIMPLE_STATS_COUNTER(name) STATS_COUNTER(name, 1)
 
 #define RATE_COUNTER(name, duration) do { \
-  static StatsRate hit_count(name); \
+  static base::StatsRate hit_count(name); \
   hit_count.AddTime(duration); \
 } while (0)
 
@@ -142,14 +144,14 @@ class StatsCounterTimer : protected StatsCounter {
   bool Running();
 
   // Accept a TimeDelta to increment.
-  virtual void AddTime(base::TimeDelta time);
+  virtual void AddTime(TimeDelta time);
 
  protected:
   // Compute the delta between start and stop, in milliseconds.
   void Record();
 
-  base::TimeTicks start_time_;
-  base::TimeTicks stop_time_;
+  TimeTicks start_time_;
+  TimeTicks stop_time_;
 };
 
 // A StatsRate is a timer that keeps a count of the number of intervals added so
@@ -158,7 +160,7 @@ class StatsCounterTimer : protected StatsCounter {
 class StatsRate : public StatsCounterTimer {
  public:
   // Constructs and starts the timer.
-  explicit StatsRate(const char* name);
+  explicit StatsRate(const std::string& name);
   virtual ~StatsRate();
 
   virtual void Add(int value);
@@ -189,4 +191,6 @@ template<class T> class StatsScope {
   T& timer_;
 };
 
-#endif  // BASE_STATS_COUNTERS_H__
+}  // namespace base
+
+#endif  // BASE_METRICS_STATS_COUNTERS_H_
diff --git a/base/stats_table.cc b/base/metrics/stats_table.cc
index 2ef78e8..98b2f57 100644
--- a/base/stats_table.cc
+++ b/base/metrics/stats_table.cc
@@ -1,8 +1,8 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/stats_table.h"
+#include "base/metrics/stats_table.h"
 
 #include "base/logging.h"
 #include "base/platform_thread.h"
@@ -18,6 +18,8 @@
 #include "errno.h"
 #endif
 
+namespace base {
+
 // The StatsTable uses a shared memory segment that is laid out as follows
 //
 // +-------------------------------------------+
@@ -84,23 +86,12 @@ inline int AlignedSize(int size) {
   return size + AlignOffset(size);
 }
 
-// StatsTableTLSData carries the data stored in the TLS slots for the
-// StatsTable.  This is used so that we can properly cleanup when the
-// thread exits and return the table slot.
-//
-// Each thread that calls RegisterThread in the StatsTable will have
-// a StatsTableTLSData stored in its TLS.
-struct StatsTableTLSData {
-  StatsTable* table;
-  int slot;
-};
-
 }  // namespace
 
-// The StatsTablePrivate maintains convenience pointers into the
+// The StatsTable::Private maintains convenience pointers into the
 // shared memory segment.  Use this class to keep the data structure
 // clean and accessible.
-class StatsTablePrivate {
+class StatsTable::Private {
  public:
   // Various header information contained in the memory mapped segment.
   struct TableHeader {
@@ -110,12 +101,12 @@ class StatsTablePrivate {
     int max_threads;
   };
 
-  // Construct a new StatsTablePrivate based on expected size parameters, or
+  // Construct a new Private based on expected size parameters, or
   // return NULL on failure.
-  static StatsTablePrivate* New(const std::string& name, int size,
+  static Private* New(const std::string& name, int size,
                                 int max_threads, int max_counters);
 
-  base::SharedMemory* shared_memory() { return &shared_memory_; }
+  SharedMemory* shared_memory() { return &shared_memory_; }
 
   // Accessors for our header pointers
   TableHeader* table_header() const { return table_header_; }
@@ -145,7 +136,7 @@ class StatsTablePrivate {
 
  private:
   // Constructor is private because you should use New() instead.
-  StatsTablePrivate() {}
+  Private() {}
 
   // Initializes the table on first access.  Sets header values
   // appropriately and zeroes all counters.
@@ -155,7 +146,7 @@ class StatsTablePrivate {
   // Initializes our in-memory pointers into a pre-created StatsTable.
   void ComputeMappedPointers(void* memory);
 
-  base::SharedMemory shared_memory_;
+  SharedMemory shared_memory_;
   TableHeader* table_header_;
   char* thread_names_table_;
   PlatformThreadId* thread_tid_table_;
@@ -165,11 +156,11 @@ class StatsTablePrivate {
 };
 
 // static
-StatsTablePrivate* StatsTablePrivate::New(const std::string& name,
-                                          int size,
-                                          int max_threads,
-                                          int max_counters) {
-  scoped_ptr<StatsTablePrivate> priv(new StatsTablePrivate());
+StatsTable::Private* StatsTable::Private::New(const std::string& name,
+                                              int size,
+                                              int max_threads,
+                                              int max_counters) {
+  scoped_ptr<Private> priv(new Private());
   if (!priv->shared_memory_.Create(name, false, true, size))
     return NULL;
   if (!priv->shared_memory_.Map(size))
@@ -189,9 +180,9 @@ StatsTablePrivate* StatsTablePrivate::New(const std::string& name,
   return priv.release();
 }
 
-void StatsTablePrivate::InitializeTable(void* memory, int size,
-                                        int max_counters,
-                                        int max_threads) {
+void StatsTable::Private::InitializeTable(void* memory, int size,
+                                          int max_counters,
+                                          int max_threads) {
   // Zero everything.
   memset(memory, 0, size);
 
@@ -203,7 +194,7 @@ void StatsTablePrivate::InitializeTable(void* memory, int size,
   header->max_threads = max_threads;
 }
 
-void StatsTablePrivate::ComputeMappedPointers(void* memory) {
+void StatsTable::Private::ComputeMappedPointers(void* memory) {
   char* data = static_cast<char*>(memory);
   int offset = 0;
 
@@ -238,7 +229,16 @@ void StatsTablePrivate::ComputeMappedPointers(void* memory) {
   DCHECK_EQ(offset, size());
 }
 
-
+// TLSData carries the data stored in the TLS slots for the
+// StatsTable.  This is used so that we can properly cleanup when the
+// thread exits and return the table slot.
+//
+// Each thread that calls RegisterThread in the StatsTable will have
+// a TLSData stored in its TLS.
+struct StatsTable::TLSData {
+  StatsTable* table;
+  int slot;
+};
 
 // We keep a singleton table which can be easily accessed.
 StatsTable* StatsTable::global_table_ = NULL;
@@ -248,14 +248,14 @@ StatsTable::StatsTable(const std::string& name, int max_threads,
     : impl_(NULL),
       tls_index_(SlotReturnFunction) {
   int table_size =
-    AlignedSize(sizeof(StatsTablePrivate::TableHeader)) +
+    AlignedSize(sizeof(Private::TableHeader)) +
     AlignedSize((max_counters * sizeof(char) * kMaxCounterNameLength)) +
     AlignedSize((max_threads * sizeof(char) * kMaxThreadNameLength)) +
     AlignedSize(max_threads * sizeof(int)) +
     AlignedSize(max_threads * sizeof(int)) +
     AlignedSize((sizeof(int) * (max_counters * max_threads)));
 
-  impl_ = StatsTablePrivate::New(name, table_size, max_threads, max_counters);
+  impl_ = Private::New(name, table_size, max_threads, max_counters);
 
   if (!impl_)
     PLOG(ERROR) << "StatsTable did not initialize";
@@ -287,7 +287,7 @@ int StatsTable::RegisterThread(const std::string& name) {
   // so that two threads don't grab the same slot.  Fortunately,
   // thread creation shouldn't happen in inner loops.
   {
-    base::SharedMemoryAutoLock lock(impl_->shared_memory());
+    SharedMemoryAutoLock lock(impl_->shared_memory());
     slot = FindEmptyThread();
     if (!slot) {
       return 0;
@@ -297,23 +297,23 @@ int StatsTable::RegisterThread(const std::string& name) {
     std::string thread_name = name;
     if (name.empty())
       thread_name = kUnknownName;
-    base::strlcpy(impl_->thread_name(slot), thread_name.c_str(),
-                  kMaxThreadNameLength);
+    strlcpy(impl_->thread_name(slot), thread_name.c_str(),
+            kMaxThreadNameLength);
     *(impl_->thread_tid(slot)) = PlatformThread::CurrentId();
-    *(impl_->thread_pid(slot)) = base::GetCurrentProcId();
+    *(impl_->thread_pid(slot)) = GetCurrentProcId();
   }
 
   // Set our thread local storage.
-  StatsTableTLSData* data = new StatsTableTLSData;
+  TLSData* data = new TLSData;
   data->table = this;
   data->slot = slot;
   tls_index_.Set(data);
   return slot;
 }
 
-StatsTableTLSData* StatsTable::GetTLSData() const {
-  StatsTableTLSData* data =
-    static_cast<StatsTableTLSData*>(tls_index_.Get());
+StatsTable::TLSData* StatsTable::GetTLSData() const {
+  TLSData* data =
+    static_cast<TLSData*>(tls_index_.Get());
   if (!data)
     return NULL;
 
@@ -326,7 +326,7 @@ void StatsTable::UnregisterThread() {
   UnregisterThread(GetTLSData());
 }
 
-void StatsTable::UnregisterThread(StatsTableTLSData* data) {
+void StatsTable::UnregisterThread(TLSData* data) {
   if (!data)
     return;
   DCHECK(impl_);
@@ -344,7 +344,7 @@ void StatsTable::SlotReturnFunction(void* data) {
   // This is called by the TLS destructor, which on some platforms has
   // already cleared the TLS info, so use the tls_data argument
   // rather than trying to fetch it ourselves.
-  StatsTableTLSData* tls_data = static_cast<StatsTableTLSData*>(data);
+  TLSData* tls_data = static_cast<TLSData*>(data);
   if (tls_data) {
     DCHECK(tls_data->table);
     tls_data->table->UnregisterThread(tls_data);
@@ -367,7 +367,7 @@ int StatsTable::CountThreadsRegistered() const {
 }
 
 int StatsTable::GetSlot() const {
-  StatsTableTLSData* data = GetTLSData();
+  TLSData* data = GetTLSData();
   if (!data)
     return 0;
   return data->slot;
@@ -448,7 +448,7 @@ int StatsTable::AddCounter(const std::string& name) {
   {
     // To add a counter to the shared memory, we need the
     // shared memory lock.
-    base::SharedMemoryAutoLock lock(impl_->shared_memory());
+    SharedMemoryAutoLock lock(impl_->shared_memory());
 
     // We have space, so create a new counter.
     counter_id = FindCounterOrEmptyRow(name);
@@ -458,8 +458,8 @@ int StatsTable::AddCounter(const std::string& name) {
     std::string counter_name = name;
     if (name.empty())
       counter_name = kUnknownName;
-    base::strlcpy(impl_->counter_name(counter_id), counter_name.c_str(),
-                  kMaxCounterNameLength);
+    strlcpy(impl_->counter_name(counter_id), counter_name.c_str(),
+            kMaxCounterNameLength);
   }
 
   // now add to our in-memory cache
@@ -549,3 +549,5 @@ int* StatsTable::FindLocation(const char* name) {
   // Now we can find the location in the table.
   return table->GetLocation(counter, slot);
 }
+
+}  // namespace base
diff --git a/base/stats_table.h b/base/metrics/stats_table.h
index 3522876..e83039c 100644
--- a/base/stats_table.h
+++ b/base/metrics/stats_table.h
@@ -17,21 +17,18 @@
 // threads/processes which can use it.
 //
 
-#ifndef BASE_STATS_TABLE_H__
-#define BASE_STATS_TABLE_H__
+#ifndef BASE_METRICS_STATS_TABLE_H_
+#define BASE_METRICS_STATS_TABLE_H_
 #pragma once
 
 #include <string>
+
 #include "base/basictypes.h"
 #include "base/hash_tables.h"
 #include "base/lock.h"
 #include "base/thread_local_storage.h"
 
-class StatsTablePrivate;
-
-namespace {
-struct StatsTableTLSData;
-}
+namespace base {
 
 class StatsTable {
  public:
@@ -133,6 +130,9 @@ class StatsTable {
   static int* FindLocation(const char *name);
 
  private:
+  class Private;
+  struct TLSData;
+
   // Returns the space occupied by a thread in the table.  Generally used
   // if a thread terminates but the process continues.  This function
   // does not zero out the thread's counters.
@@ -141,7 +141,7 @@ class StatsTable {
 
   // This variant expects the tls data to be passed in, so it is safe to
   // call from inside a posix tls destructor (see doc for pthread_key_create).
-  void UnregisterThread(StatsTableTLSData* tls_data);
+  void UnregisterThread(TLSData* tls_data);
 
   // The SlotReturnFunction is called at thread exit for each thread
   // which used the StatsTable.
@@ -169,13 +169,15 @@ class StatsTable {
 
   // Get the TLS data for the calling thread.  Returns NULL if none is
   // initialized.
-  StatsTableTLSData* GetTLSData() const;
+  TLSData* GetTLSData() const;
 
-  typedef base::hash_map<std::string, int> CountersMap;
+  typedef hash_map<std::string, int> CountersMap;
+
+  Private* impl_;
 
-  StatsTablePrivate* impl_;
   // The counters_lock_ protects the counters_ hash table.
   Lock counters_lock_;
+
   // The counters_ hash map is an in-memory hash of the counters.
   // It is used for quick lookup of counters, but is cannot be used
   // as a substitute for what is in the shared memory.  Even though
@@ -189,4 +191,6 @@ class StatsTable {
   DISALLOW_COPY_AND_ASSIGN(StatsTable);
 };
 
-#endif  // BASE_STATS_TABLE_H__
+}  // namespace base
+
+#endif  // BASE_METRICS_STATS_TABLE_H_
diff --git a/base/stats_table_unittest.cc b/base/metrics/stats_table_unittest.cc
index f926f29..c9eb9a2 100644
--- a/base/stats_table_unittest.cc
+++ b/base/metrics/stats_table_unittest.cc
@@ -1,17 +1,12 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#if defined(OS_WIN)
-#include <process.h>
-#include <windows.h>
-#endif
-
 #include "base/platform_thread.h"
 #include "base/simple_thread.h"
 #include "base/shared_memory.h"
-#include "base/stats_table.h"
-#include "base/stats_counters.h"
+#include "base/metrics/stats_table.h"
+#include "base/metrics/stats_counters.h"
 #include "base/string_piece.h"
 #include "base/string_util.h"
 #include "base/test/multiprocess_test.h"
@@ -24,7 +19,7 @@ namespace base {
 class StatsTableTest : public MultiProcessTest {
  public:
   void DeleteShmem(const std::string& name) {
-    base::SharedMemory mem;
+    SharedMemory mem;
     mem.Delete(name);
   }
 };
@@ -77,10 +72,11 @@ const std::string kCounterMixed = "CounterMixed";
 // The number of thread loops that we will do.
 const int kThreadLoops = 100;
 
-class StatsTableThread : public base::SimpleThread {
+class StatsTableThread : public SimpleThread {
  public:
   StatsTableThread(std::string name, int id)
-      : base::SimpleThread(name), id_(id) { }
+      : SimpleThread(name),
+      id_(id) {}
   virtual void Run();
  private:
   int id_;
@@ -208,13 +204,13 @@ TEST_F(StatsTableTest, FLAKY_MultipleProcesses) {
   // Spawn the processes.
   for (int16 index = 0; index < kMaxProcs; index++) {
     procs[index] = this->SpawnChild("StatsTableMultipleProcessMain", false);
-    EXPECT_NE(base::kNullProcessHandle, procs[index]);
+    EXPECT_NE(kNullProcessHandle, procs[index]);
   }
 
   // Wait for the processes to finish.
   for (int index = 0; index < kMaxProcs; index++) {
     EXPECT_TRUE(WaitForSingleProcess(procs[index], 60 * 1000));
-    base::CloseProcessHandle(procs[index]);
+    CloseProcessHandle(procs[index]);
   }
 
   StatsCounter zero_counter(kCounterZero);
diff --git a/base/process_util_win.cc b/base/process_util_win.cc
index 9b62b26..4b701e9 100644
--- a/base/process_util_win.cc
+++ b/base/process_util_win.cc
@@ -14,8 +14,8 @@
 
 #include "base/command_line.h"
 #include "base/debug_util.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/scoped_handle_win.h"
 #include "base/scoped_ptr.h"
 #include "base/win_util.h"
diff --git a/base/worker_pool_mac.mm b/base/worker_pool_mac.mm
index b9d4192..a301bf8 100644
--- a/base/worker_pool_mac.mm
+++ b/base/worker_pool_mac.mm
@@ -1,16 +1,16 @@
-// Copyright (c) 2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/worker_pool_mac.h"
 
-#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #import "base/scoped_nsautorelease_pool.h"
 #include "base/scoped_ptr.h"
 #import "base/singleton_objc.h"
 #include "base/task.h"
+#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
 
 // When C++ exceptions are disabled, the C++ library defines |try| and
 // |catch| so as to allow exception-expecting C++ code to build properly when
diff --git a/chrome/app/chrome_dll_main.cc b/chrome/app/chrome_dll_main.cc
index c08e109..dad27d8 100644
--- a/chrome/app/chrome_dll_main.cc
+++ b/chrome/app/chrome_dll_main.cc
@@ -40,11 +40,11 @@
 #include "base/debug_util.h"
 #include "base/i18n/icu_util.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_counters.h"
+#include "base/metrics/stats_table.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/scoped_nsautorelease_pool.h"
-#include "base/stats_counters.h"
-#include "base/stats_table.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
@@ -450,9 +450,9 @@ void InitializeStatsTable(base::ProcessId browser_pid,
     std::string statsfile =
         StringPrintf("%s-%u", chrome::kStatsFilename,
                      static_cast<unsigned int>(browser_pid));
-    StatsTable *stats_table = new StatsTable(statsfile,
+    base::StatsTable *stats_table = new base::StatsTable(statsfile,
         chrome::kStatsMaxThreads, chrome::kStatsMaxCounters);
-    StatsTable::set_current(stats_table);
+    base::StatsTable::set_current(stats_table);
   }
 }
 
@@ -705,7 +705,7 @@ int ChromeMain(int argc, char** argv) {
 
   InitializeStatsTable(browser_pid, parsed_command_line);
 
-  StatsScope<StatsCounterTimer>
+  base::StatsScope<base::StatsCounterTimer>
       startup_timer(chrome::Counters::chrome_main());
 
   // Enable the heap profiler as early as possible!
diff --git a/chrome/browser/autocomplete/autocomplete_edit.cc b/chrome/browser/autocomplete/autocomplete_edit.cc
index dd6b14c..d5faec3 100644
--- a/chrome/browser/autocomplete/autocomplete_edit.cc
+++ b/chrome/browser/autocomplete/autocomplete_edit.cc
@@ -7,7 +7,7 @@
 #include <string>
 
 #include "base/basictypes.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/app/chrome_dll_resource.h"
diff --git a/chrome/browser/autocomplete/history_contents_provider.cc b/chrome/browser/autocomplete/history_contents_provider.cc
index 911f429..06e46d2 100644
--- a/chrome/browser/autocomplete/history_contents_provider.cc
+++ b/chrome/browser/autocomplete/history_contents_provider.cc
@@ -5,7 +5,7 @@
 #include "chrome/browser/autocomplete/history_contents_provider.h"
 
 #include "base/callback.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
diff --git a/chrome/browser/autocomplete/history_quick_provider.cc b/chrome/browser/autocomplete/history_quick_provider.cc
index 776c343..04d1c7e1 100644
--- a/chrome/browser/autocomplete/history_quick_provider.cc
+++ b/chrome/browser/autocomplete/history_quick_provider.cc
@@ -5,7 +5,6 @@
 #include "chrome/browser/autocomplete/history_quick_provider.h"
 
 #include "base/basictypes.h"
-#include "base/histogram.h"
 #include "base/i18n/word_iterator.h"
 #include "base/string_util.h"
 #include "base/logging.h"
diff --git a/chrome/browser/autocomplete/history_url_provider.cc b/chrome/browser/autocomplete/history_url_provider.cc
index 234bed4..f86e5db 100644
--- a/chrome/browser/autocomplete/history_url_provider.cc
+++ b/chrome/browser/autocomplete/history_url_provider.cc
@@ -7,8 +7,8 @@
 #include <algorithm>
 
 #include "base/basictypes.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/history/history.h"
diff --git a/chrome/browser/autofill/autofill_cc_infobar_delegate.cc b/chrome/browser/autofill/autofill_cc_infobar_delegate.cc
index bc47eca..01b49eb 100644
--- a/chrome/browser/autofill/autofill_cc_infobar_delegate.cc
+++ b/chrome/browser/autofill/autofill_cc_infobar_delegate.cc
@@ -6,7 +6,7 @@
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "chrome/browser/autofill/autofill_cc_infobar.h"
 #include "chrome/browser/autofill/autofill_manager.h"
 #include "chrome/browser/browser_list.h"
diff --git a/chrome/browser/automation/automation_resource_message_filter.cc b/chrome/browser/automation/automation_resource_message_filter.cc
index 9230b86..abdf099 100644
--- a/chrome/browser/automation/automation_resource_message_filter.cc
+++ b/chrome/browser/automation/automation_resource_message_filter.cc
@@ -4,8 +4,8 @@
 
 #include "chrome/browser/automation/automation_resource_message_filter.h"
 
-#include "base/histogram.h"
 #include "base/path_service.h"
+#include "base/metrics/histogram.h"
 #include "base/stl_util-inl.h"
 #include "chrome/browser/automation/url_request_automation_job.h"
 #include "chrome/browser/browser_thread.h"
@@ -396,7 +396,7 @@ void AutomationResourceMessageFilter::OnGetFilteredInetHitCount(
 void AutomationResourceMessageFilter::OnRecordHistograms(
     const std::vector<std::string>& histogram_list) {
   for (size_t index = 0; index < histogram_list.size(); ++index) {
-    Histogram::DeserializeHistogramInfo(histogram_list[index]);
+    base::Histogram::DeserializeHistogramInfo(histogram_list[index]);
   }
 }
 
diff --git a/chrome/browser/bookmarks/bookmark_storage.cc b/chrome/browser/bookmarks/bookmark_storage.cc
index 4debf38..6cbe433 100644
--- a/chrome/browser/bookmarks/bookmark_storage.cc
+++ b/chrome/browser/bookmarks/bookmark_storage.cc
@@ -6,7 +6,7 @@
 
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "chrome/browser/bookmarks/bookmark_codec.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
diff --git a/chrome/browser/browser.cc b/chrome/browser/browser.cc
index c8f3ceb..c4f0b2a 100644
--- a/chrome/browser/browser.cc
+++ b/chrome/browser/browser.cc
@@ -16,8 +16,8 @@
 #include "app/l10n_util.h"
 #include "base/base_paths.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/string_util.h"
 #include "base/thread.h"
diff --git a/chrome/browser/browser_about_handler.cc b/chrome/browser/browser_about_handler.cc
index 03afaaf..9a75983 100644
--- a/chrome/browser/browser_about_handler.cc
+++ b/chrome/browser/browser_about_handler.cc
@@ -12,11 +12,11 @@
 #include "app/resource_bundle.h"
 #include "base/callback.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/i18n/number_formatting.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/stats_table.h"
 #include "base/path_service.h"
 #include "base/platform_thread.h"
-#include "base/stats_table.h"
 #include "base/stringprintf.h"
 #include "base/string_number_conversions.h"
 #include "base/string_piece.h"
@@ -403,7 +403,7 @@ std::string AboutHistograms(const std::string& query) {
   current_synchronizer->FetchRendererHistogramsSynchronously(wait_time);
 
   std::string data;
-  StatisticsRecorder::WriteHTMLGraph(query, &data);
+  base::StatisticsRecorder::WriteHTMLGraph(query, &data);
   return data;
 }
 
@@ -428,7 +428,7 @@ std::string AboutStats() {
   // stats computations across runs.
   static DictionaryValue root;
 
-  StatsTable* table = StatsTable::current();
+  base::StatsTable* table = base::StatsTable::current();
   if (!table)
     return std::string();
 
diff --git a/chrome/browser/browser_child_process_host.cc b/chrome/browser/browser_child_process_host.cc
index 2c8ba34..a317f26 100644
--- a/chrome/browser/browser_child_process_host.cc
+++ b/chrome/browser/browser_child_process_host.cc
@@ -6,8 +6,8 @@
 
 #include "base/command_line.h"
 #include "base/file_path.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/singleton.h"
diff --git a/chrome/browser/browser_init.cc b/chrome/browser/browser_init.cc
index 6e5cd9a..e8d3945 100644
--- a/chrome/browser/browser_init.cc
+++ b/chrome/browser/browser_init.cc
@@ -11,7 +11,7 @@
 #include "base/environment.h"
 #include "base/event_recorder.h"
 #include "base/file_path.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/scoped_ptr.h"
 #include "base/string_number_conversions.h"
@@ -490,7 +490,7 @@ bool BrowserInit::LaunchWithProfile::Launch(Profile* profile,
     chrome_browser_net::EnablePredictor(false);
 
   if (command_line_.HasSwitch(switches::kDumpHistogramsOnExit))
-    StatisticsRecorder::set_dump_on_exit(true);
+    base::StatisticsRecorder::set_dump_on_exit(true);
 
   if (command_line_.HasSwitch(switches::kRemoteShellPort)) {
     std::string port_str =
diff --git a/chrome/browser/browser_list.cc b/chrome/browser/browser_list.cc
index 0803db5..2652c1a 100644
--- a/chrome/browser/browser_list.cc
+++ b/chrome/browser/browser_list.cc
@@ -4,9 +4,9 @@
 
 #include "chrome/browser/browser_list.h"
 
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_shutdown.h"
diff --git a/chrome/browser/browser_main.cc b/chrome/browser/browser_main.cc
index 7dce691..0cbcc66 100644
--- a/chrome/browser/browser_main.cc
+++ b/chrome/browser/browser_main.cc
@@ -14,10 +14,10 @@
 #include "app/system_monitor.h"
 #include "base/at_exit.h"
 #include "base/command_line.h"
-#include "base/field_trial.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
 #include "base/scoped_nsautorelease_pool.h"
 #include "base/path_service.h"
 #include "base/platform_thread.h"
@@ -206,11 +206,11 @@ void BrowserMainParts::EarlyInitialization() {
 // on browsing. Too large a value might cause us to run into SYN flood detection
 // mechanisms.
 void BrowserMainParts::ConnectionFieldTrial() {
-  const FieldTrial::Probability kConnectDivisor = 100;
-  const FieldTrial::Probability kConnectProbability = 1;  // 1% probability
+  const base::FieldTrial::Probability kConnectDivisor = 100;
+  const base::FieldTrial::Probability kConnectProbability = 1;  // 1% prob.
 
-  scoped_refptr<FieldTrial> connect_trial =
-      new FieldTrial("ConnCountImpact", kConnectDivisor);
+  scoped_refptr<base::FieldTrial> connect_trial =
+      new base::FieldTrial("ConnCountImpact", kConnectDivisor);
 
   const int connect_5 = connect_trial->AppendGroup("conn_count_5",
                                                    kConnectProbability);
@@ -225,7 +225,7 @@ void BrowserMainParts::ConnectionFieldTrial() {
   // probability value will be assigned to all the other groups, while
   // preserving the remainder of the of probability space to the default value.
   const int connect_6 = connect_trial->AppendGroup("conn_count_6",
-      FieldTrial::kAllRemainingProbability);
+      base::FieldTrial::kAllRemainingProbability);
 
   const int connect_trial_group = connect_trial->group();
 
@@ -250,12 +250,12 @@ void BrowserMainParts::ConnectionFieldTrial() {
 // result in more ERR_CONNECT_RESETs, requiring one RTT to receive the RST
 // packet and possibly another RTT to re-establish the connection.
 void BrowserMainParts::SocketTimeoutFieldTrial() {
-  const FieldTrial::Probability kIdleSocketTimeoutDivisor = 100;
+  const base::FieldTrial::Probability kIdleSocketTimeoutDivisor = 100;
   // 1% probability for all experimental settings.
-  const FieldTrial::Probability kSocketTimeoutProbability = 1;
+  const base::FieldTrial::Probability kSocketTimeoutProbability = 1;
 
-  scoped_refptr<FieldTrial> socket_timeout_trial =
-      new FieldTrial("IdleSktToImpact", kIdleSocketTimeoutDivisor);
+  scoped_refptr<base::FieldTrial> socket_timeout_trial =
+      new base::FieldTrial("IdleSktToImpact", kIdleSocketTimeoutDivisor);
 
   const int socket_timeout_5 =
       socket_timeout_trial->AppendGroup("idle_timeout_5",
@@ -268,7 +268,7 @@ void BrowserMainParts::SocketTimeoutFieldTrial() {
                                         kSocketTimeoutProbability);
   const int socket_timeout_60 =
       socket_timeout_trial->AppendGroup("idle_timeout_60",
-                                        FieldTrial::kAllRemainingProbability);
+          base::FieldTrial::kAllRemainingProbability);
 
   const int idle_to_trial_group = socket_timeout_trial->group();
 
@@ -286,12 +286,12 @@ void BrowserMainParts::SocketTimeoutFieldTrial() {
 }
 
 void BrowserMainParts::ProxyConnectionsFieldTrial() {
-  const FieldTrial::Probability kProxyConnectionsDivisor = 100;
+  const base::FieldTrial::Probability kProxyConnectionsDivisor = 100;
   // 25% probability
-  const FieldTrial::Probability kProxyConnectionProbability = 1;
+  const base::FieldTrial::Probability kProxyConnectionProbability = 1;
 
-  scoped_refptr<FieldTrial> proxy_connection_trial =
-      new FieldTrial("ProxyConnectionImpact", kProxyConnectionsDivisor);
+  scoped_refptr<base::FieldTrial> proxy_connection_trial =
+      new base::FieldTrial("ProxyConnectionImpact", kProxyConnectionsDivisor);
 
   // The number of max sockets per group cannot be greater than the max number
   // of sockets per proxy server.  We tried using 8, and it can easily
@@ -309,7 +309,7 @@ void BrowserMainParts::ProxyConnectionsFieldTrial() {
   // which allows for cleaner and quicker changes down the line if needed.
   const int proxy_connections_32 =
       proxy_connection_trial->AppendGroup("proxy_connections_32",
-                                          FieldTrial::kAllRemainingProbability);
+          base::FieldTrial::kAllRemainingProbability);
 
   const int proxy_connections_trial_group = proxy_connection_trial->group();
 
@@ -338,15 +338,16 @@ void BrowserMainParts::SpdyFieldTrial() {
         parsed_command_line().GetSwitchValueASCII(switches::kUseSpdy);
     net::HttpNetworkLayer::EnableSpdy(spdy_mode);
   } else {
-    const FieldTrial::Probability kSpdyDivisor = 100;
-    FieldTrial::Probability npnhttp_probability = 10;  // 10% to preclude SPDY.
-    scoped_refptr<FieldTrial> trial =
-        new FieldTrial("SpdyImpact", kSpdyDivisor);
+    const base::FieldTrial::Probability kSpdyDivisor = 100;
+    // 10% to preclude SPDY.
+    base::FieldTrial::Probability npnhttp_probability = 10;
+    scoped_refptr<base::FieldTrial> trial =
+        new base::FieldTrial("SpdyImpact", kSpdyDivisor);
     // npn with only http support, no spdy.
     int npn_http_grp = trial->AppendGroup("npn_with_http", npnhttp_probability);
     // npn with spdy support.
     int npn_spdy_grp = trial->AppendGroup("npn_with_spdy",
-                                          FieldTrial::kAllRemainingProbability);
+        base::FieldTrial::kAllRemainingProbability);
     int trial_grp = trial->group();
     if (trial_grp == npn_http_grp) {
       is_spdy_trial = true;
@@ -368,14 +369,14 @@ void BrowserMainParts::PrefetchFieldTrial() {
   else if (parsed_command_line().HasSwitch(switches::kDisableContentPrefetch)) {
     ResourceDispatcherHost::set_is_prefetch_enabled(false);
   } else {
-    const FieldTrial::Probability kPrefetchDivisor = 1000;
-    const FieldTrial::Probability no_prefetch_probability = 500;
-    scoped_refptr<FieldTrial> trial =
-        new FieldTrial("Prefetch", kPrefetchDivisor);
+    const base::FieldTrial::Probability kPrefetchDivisor = 1000;
+    const base::FieldTrial::Probability no_prefetch_probability = 500;
+    scoped_refptr<base::FieldTrial> trial =
+        new base::FieldTrial("Prefetch", kPrefetchDivisor);
     trial->AppendGroup("ContentPrefetchDisabled", no_prefetch_probability);
     const int yes_prefetch_grp =
         trial->AppendGroup("ContentPrefetchEnabled",
-                           FieldTrial::kAllRemainingProbability);
+                           base::FieldTrial::kAllRemainingProbability);
     const int trial_grp = trial->group();
     ResourceDispatcherHost::set_is_prefetch_enabled(
         trial_grp == yes_prefetch_grp);
@@ -394,16 +395,17 @@ void BrowserMainParts::ConnectBackupJobsFieldTrial() {
     net::internal::ClientSocketPoolBaseHelper::set_connect_backup_jobs_enabled(
         false);
   } else {
-    const FieldTrial::Probability kConnectBackupJobsDivisor = 100;
-    // 50% probability.
-    const FieldTrial::Probability kConnectBackupJobsProbability = 1;  // 1%.
-    scoped_refptr<FieldTrial> trial = new FieldTrial("ConnnectBackupJobs",
-                                                     kConnectBackupJobsDivisor);
+    const base::FieldTrial::Probability kConnectBackupJobsDivisor = 100;
+    // 1% probability.
+    const base::FieldTrial::Probability kConnectBackupJobsProbability = 1;
+    scoped_refptr<base::FieldTrial> trial =
+        new base::FieldTrial("ConnnectBackupJobs",
+                             kConnectBackupJobsDivisor);
     trial->AppendGroup("ConnectBackupJobsDisabled",
                        kConnectBackupJobsProbability);
     const int connect_backup_jobs_enabled =
         trial->AppendGroup("ConnectBackupJobsEnabled",
-                           FieldTrial::kAllRemainingProbability);
+                           base::FieldTrial::kAllRemainingProbability);
     const int trial_group = trial->group();
     net::internal::ClientSocketPoolBaseHelper::set_connect_backup_jobs_enabled(
         trial_group == connect_backup_jobs_enabled);
@@ -942,7 +944,7 @@ int BrowserMain(const MainFunctionParams& parameters) {
   InitializeBrokerServices(parameters, parsed_command_line);
 
   // Initialize histogram statistics gathering system.
-  StatisticsRecorder statistics;
+  base::StatisticsRecorder statistics;
 
   PrefService* local_state = InitializeLocalState(parsed_command_line,
                                                   is_first_run);
@@ -1354,10 +1356,10 @@ int BrowserMain(const MainFunctionParams& parameters) {
   // Perform A/B test to measure global impact of SDCH support.
   // Set up a field trial to see what disabling SDCH does to latency of page
   // layout globally.
-  FieldTrial::Probability kSDCH_DIVISOR = 1000;
-  FieldTrial::Probability kSDCH_DISABLE_PROBABILITY = 1;  // 0.1% probability.
-  scoped_refptr<FieldTrial> sdch_trial =
-      new FieldTrial("GlobalSdch", kSDCH_DIVISOR);
+  base::FieldTrial::Probability kSDCH_DIVISOR = 1000;
+  base::FieldTrial::Probability kSDCH_DISABLE_PROBABILITY = 1;  // 0.1% prob.
+  scoped_refptr<base::FieldTrial> sdch_trial =
+      new base::FieldTrial("GlobalSdch", kSDCH_DIVISOR);
 
   // Use default of "" so that all domains are supported.
   std::string sdch_supported_domain("");
@@ -1368,7 +1370,7 @@ int BrowserMain(const MainFunctionParams& parameters) {
     sdch_trial->AppendGroup("global_disable_sdch",
                             kSDCH_DISABLE_PROBABILITY);
     int sdch_enabled = sdch_trial->AppendGroup("global_enable_sdch",
-        FieldTrial::kAllRemainingProbability);
+        base::FieldTrial::kAllRemainingProbability);
     if (sdch_enabled != sdch_trial->group())
       sdch_supported_domain = "never_enabled_sdch_for_any_domain";
   }
diff --git a/chrome/browser/browser_main.h b/chrome/browser/browser_main.h
index 033fb1b..9154a4c 100644
--- a/chrome/browser/browser_main.h
+++ b/chrome/browser/browser_main.h
@@ -7,7 +7,7 @@
 #pragma once
 
 #include "base/basictypes.h"
-#include "base/field_trial.h"
+#include "base/metrics/field_trial.h"
 #include "base/scoped_ptr.h"
 #include "base/tracked_objects.h"
 
@@ -140,7 +140,7 @@ class BrowserMainParts {
 #endif
 
   // Statistical testing infrastructure for the entire browser.
-  FieldTrialList field_trial_;
+  base::FieldTrialList field_trial_;
 
   // Members initialized in |MainMessageLoopStart()| ---------------------------
   scoped_ptr<MessageLoop> main_message_loop_;
diff --git a/chrome/browser/browser_shutdown.cc b/chrome/browser/browser_shutdown.cc
index f9cc83c..9e7d411 100644
--- a/chrome/browser/browser_shutdown.cc
+++ b/chrome/browser/browser_shutdown.cc
@@ -10,7 +10,7 @@
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/string_number_conversions.h"
diff --git a/chrome/browser/browser_trial.h b/chrome/browser/browser_trial.h
index 9af5a27..c1a3290 100644
--- a/chrome/browser/browser_trial.h
+++ b/chrome/browser/browser_trial.h
@@ -9,7 +9,7 @@
 #define CHROME_BROWSER_BROWSER_TRIAL_H_
 #pragma once
 
-#include "base/field_trial.h"
+#include "base/basictypes.h"
 
 // Currently we use this as a name space, to hold static shared constants which
 // define current and past trials.
diff --git a/chrome/browser/chrome_browser_application_mac.mm b/chrome/browser/chrome_browser_application_mac.mm
index f696e96..b4bb7cb 100644
--- a/chrome/browser/chrome_browser_application_mac.mm
+++ b/chrome/browser/chrome_browser_application_mac.mm
@@ -4,8 +4,8 @@
 
 #import "chrome/browser/chrome_browser_application_mac.h"
 
-#import "base/histogram.h"
 #import "base/logging.h"
+#import "base/metrics/histogram.h"
 #import "base/scoped_nsobject.h"
 #import "base/sys_string_conversions.h"
 #import "chrome/app/breakpad_mac.h"
diff --git a/chrome/browser/chrome_browser_application_mac_unittest.mm b/chrome/browser/chrome_browser_application_mac_unittest.mm
index d5f26c5..c5a589c 100644
--- a/chrome/browser/chrome_browser_application_mac_unittest.mm
+++ b/chrome/browser/chrome_browser_application_mac_unittest.mm
@@ -4,10 +4,13 @@
 
 #import <Cocoa/Cocoa.h>
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #import "chrome/browser/chrome_browser_application_mac.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+using base::Histogram;
+using base::StatisticsRecorder;
+
 namespace chrome_browser_application_mac {
 
 // Generate an NSException with the given name.
diff --git a/chrome/browser/chrome_plugin_host.cc b/chrome/browser/chrome_plugin_host.cc
index 3b48914..76d4756 100644
--- a/chrome/browser/chrome_plugin_host.cc
+++ b/chrome/browser/chrome_plugin_host.cc
@@ -10,8 +10,8 @@
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/perftimer.h"
 #include "base/singleton.h"
diff --git a/chrome/browser/chromeos/boot_times_loader.cc b/chrome/browser/chromeos/boot_times_loader.cc
index 8a52e39..97172be 100644
--- a/chrome/browser/chromeos/boot_times_loader.cc
+++ b/chrome/browser/chromeos/boot_times_loader.cc
@@ -9,8 +9,8 @@
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/process_util.h"
 #include "base/singleton.h"
 #include "base/string_number_conversions.h"
diff --git a/chrome/browser/chromeos/external_metrics.cc b/chrome/browser/chromeos/external_metrics.cc
index 6224f22..73e24d8 100644
--- a/chrome/browser/chromeos/external_metrics.cc
+++ b/chrome/browser/chromeos/external_metrics.cc
@@ -15,7 +15,7 @@
 
 #include "base/basictypes.h"
 #include "base/eintr_wrapper.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/perftimer.h"
 #include "base/time.h"
 #include "chrome/browser/browser_thread.h"
@@ -91,8 +91,8 @@ void ExternalMetrics::RecordHistogram(const char* histogram_data) {
   }
   // Do not use the UMA_HISTOGRAM_... macros here.  They cache the Histogram
   // instance and thus only work if |name| is constant.
-  scoped_refptr<Histogram> counter = Histogram::FactoryGet(
-      name, min, max, nbuckets, Histogram::kUmaTargetedHistogramFlag);
+  scoped_refptr<base::Histogram> counter = base::Histogram::FactoryGet(
+      name, min, max, nbuckets, base::Histogram::kUmaTargetedHistogramFlag);
   counter->Add(sample);
 }
 
@@ -106,8 +106,8 @@ void ExternalMetrics::RecordLinearHistogram(const char* histogram_data) {
   }
   // Do not use the UMA_HISTOGRAM_... macros here.  They cache the Histogram
   // instance and thus only work if |name| is constant.
-  scoped_refptr<Histogram> counter = LinearHistogram::FactoryGet(
-      name, 1, max, max + 1, Histogram::kUmaTargetedHistogramFlag);
+  scoped_refptr<base::Histogram> counter = base::LinearHistogram::FactoryGet(
+      name, 1, max, max + 1, base::Histogram::kUmaTargetedHistogramFlag);
   counter->Add(sample);
 }
 
diff --git a/chrome/browser/chromeos/external_protocol_dialog.cc b/chrome/browser/chromeos/external_protocol_dialog.cc
index e0d799f..38d1cdf 100644
--- a/chrome/browser/chromeos/external_protocol_dialog.cc
+++ b/chrome/browser/chromeos/external_protocol_dialog.cc
@@ -6,7 +6,7 @@
 
 #include "app/l10n_util.h"
 #include "app/message_box_flags.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/external_protocol_handler.h"
diff --git a/chrome/browser/chromeos/offline/offline_load_page.cc b/chrome/browser/chromeos/offline/offline_load_page.cc
index 8d9f4dd..c3b88d5 100644
--- a/chrome/browser/chromeos/offline/offline_load_page.cc
+++ b/chrome/browser/chromeos/offline/offline_load_page.cc
@@ -6,8 +6,8 @@
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
-#include "base/histogram.h"
 #include "base/i18n/rtl.h"
+#include "base/metrics/histogram.h"
 #include "base/string_piece.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
diff --git a/chrome/browser/cocoa/download_item_controller.mm b/chrome/browser/cocoa/download_item_controller.mm
index cbd18fc..a5288c2 100644
--- a/chrome/browser/cocoa/download_item_controller.mm
+++ b/chrome/browser/cocoa/download_item_controller.mm
@@ -7,8 +7,8 @@
 #include "app/l10n_util_mac.h"
 #include "app/resource_bundle.h"
 #include "app/text_elider.h"
-#include "base/histogram.h"
 #include "base/mac_util.h"
+#include "base/metrics/histogram.h"
 #include "base/string16.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
diff --git a/chrome/browser/cocoa/external_protocol_dialog.mm b/chrome/browser/cocoa/external_protocol_dialog.mm
index 3a7849a..0513ae0 100644
--- a/chrome/browser/cocoa/external_protocol_dialog.mm
+++ b/chrome/browser/cocoa/external_protocol_dialog.mm
@@ -5,8 +5,8 @@
 #import "chrome/browser/cocoa/external_protocol_dialog.h"
 
 #include "app/l10n_util_mac.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 #include "base/utf_string_conversions.h"
diff --git a/chrome/browser/cocoa/objc_method_swizzle.mm b/chrome/browser/cocoa/objc_method_swizzle.mm
index 4471efc..433bc66 100644
--- a/chrome/browser/cocoa/objc_method_swizzle.mm
+++ b/chrome/browser/cocoa/objc_method_swizzle.mm
@@ -4,7 +4,6 @@
 
 #import "chrome/browser/cocoa/objc_method_swizzle.h"
 
-#import "base/histogram.h"
 #import "base/logging.h"
 #import "base/scoped_nsobject.h"
 #import "chrome/app/breakpad_mac.h"
diff --git a/chrome/browser/cocoa/translate/translate_infobar_base.mm b/chrome/browser/cocoa/translate/translate_infobar_base.mm
index b396de8..bdc34f0 100644
--- a/chrome/browser/cocoa/translate/translate_infobar_base.mm
+++ b/chrome/browser/cocoa/translate/translate_infobar_base.mm
@@ -6,9 +6,9 @@
 #import "chrome/browser/cocoa/translate/translate_infobar_base.h"
 
 #include "app/l10n_util.h"
-#include "base/histogram.h"
-#include "base/logging.h"  // for NOTREACHED()
+#include "base/logging.h"
 #include "base/mac_util.h"
+#include "base/metrics/histogram.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/app/chrome_dll_resource.h"
 #import "chrome/browser/cocoa/hover_close_button.h"
diff --git a/chrome/browser/diagnostics/sqlite_diagnostics.cc b/chrome/browser/diagnostics/sqlite_diagnostics.cc
index 15c758a..5030301 100644
--- a/chrome/browser/diagnostics/sqlite_diagnostics.cc
+++ b/chrome/browser/diagnostics/sqlite_diagnostics.cc
@@ -8,8 +8,8 @@
 #include "app/sql/diagnostic_error_delegate.h"
 #include "app/sql/statement.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/singleton.h"
 #include "base/string_number_conversions.h"
diff --git a/chrome/browser/dom_ui/new_tab_ui.cc b/chrome/browser/dom_ui/new_tab_ui.cc
index e96f1e6..e5b5a12 100644
--- a/chrome/browser/dom_ui/new_tab_ui.cc
+++ b/chrome/browser/dom_ui/new_tab_ui.cc
@@ -11,8 +11,8 @@
 #include "app/l10n_util.h"
 #include "base/callback.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/i18n/rtl.h"
+#include "base/metrics/histogram.h"
 #include "base/singleton.h"
 #include "base/string_number_conversions.h"
 #include "base/thread.h"
diff --git a/chrome/browser/extensions/extension_host.cc b/chrome/browser/extensions/extension_host.cc
index f91c259..b35d58c 100644
--- a/chrome/browser/extensions/extension_host.cc
+++ b/chrome/browser/extensions/extension_host.cc
@@ -9,9 +9,9 @@
 #include "app/keyboard_codes.h"
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
 #include "base/singleton.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "chrome/browser/browser.h"
 #include "chrome/browser/browser_list.h"
diff --git a/chrome/browser/extensions/extension_metrics_apitest.cc b/chrome/browser/extensions/extension_metrics_apitest.cc
index 5a91e9f..ee4761c 100644
--- a/chrome/browser/extensions/extension_metrics_apitest.cc
+++ b/chrome/browser/extensions/extension_metrics_apitest.cc
@@ -4,7 +4,7 @@
 
 #include <map>
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "chrome/common/chrome_switches.h"
@@ -29,20 +29,20 @@ struct RecordedUserAction {
 // updated.
 struct RecordedHistogram {
   const char* name;  // base name of metric without extension id.
-  Histogram::ClassType type;
+  base::Histogram::ClassType type;
   int min;
   int max;
   size_t buckets;
 } g_histograms[] = {
-  {"test.h.1", Histogram::HISTOGRAM, 1, 100, 50},  // custom
-  {"test.h.2", Histogram::LINEAR_HISTOGRAM, 1, 200, 50},  // custom
-  {"test.h.3", Histogram::LINEAR_HISTOGRAM, 1, 101, 102},  // percentage
-  {"test.time", Histogram::HISTOGRAM, 1, 10000, 50},
-  {"test.medium.time", Histogram::HISTOGRAM, 1, 180000, 50},
-  {"test.long.time", Histogram::HISTOGRAM, 1, 3600000, 50},
-  {"test.count", Histogram::HISTOGRAM, 1, 1000000, 50},
-  {"test.medium.count", Histogram::HISTOGRAM, 1, 10000, 50},
-  {"test.small.count", Histogram::HISTOGRAM, 1, 100, 50},
+  {"test.h.1", base::Histogram::HISTOGRAM, 1, 100, 50},  // custom
+  {"test.h.2", base::Histogram::LINEAR_HISTOGRAM, 1, 200, 50},  // custom
+  {"test.h.3", base::Histogram::LINEAR_HISTOGRAM, 1, 101, 102},  // percentage
+  {"test.time", base::Histogram::HISTOGRAM, 1, 10000, 50},
+  {"test.medium.time", base::Histogram::HISTOGRAM, 1, 180000, 50},
+  {"test.long.time", base::Histogram::HISTOGRAM, 1, 3600000, 50},
+  {"test.count", base::Histogram::HISTOGRAM, 1, 1000000, 50},
+  {"test.medium.count", base::Histogram::HISTOGRAM, 1, 10000, 50},
+  {"test.small.count", base::Histogram::HISTOGRAM, 1, 100, 50},
 };
 
 // Build the full name of a metrics for the given extension.  Each metric
@@ -110,8 +110,8 @@ void UserActionObserver::ValidateUserActions(const Extension* extension,
 void ValidateHistograms(const Extension* extension,
                         const RecordedHistogram* recorded,
                         int count) {
-  StatisticsRecorder::Histograms histograms;
-  StatisticsRecorder::GetHistograms(&histograms);
+  base::StatisticsRecorder::Histograms histograms;
+  base::StatisticsRecorder::GetHistograms(&histograms);
 
   // Code other than the tests tun here will record some histogram values, but
   // we will ignore those. This function validates that all the histogram we
@@ -123,7 +123,7 @@ void ValidateHistograms(const Extension* extension,
 
     size_t j = 0;
     for (j = 0; j < histograms.size(); ++j) {
-      scoped_refptr<Histogram> histogram(histograms[j]);
+      scoped_refptr<base::Histogram> histogram(histograms[j]);
 
       if (name == histogram->histogram_name()) {
         EXPECT_EQ(r.type, histogram->histogram_type());
diff --git a/chrome/browser/extensions/extension_metrics_module.cc b/chrome/browser/extensions/extension_metrics_module.cc
index 0f0ab14..a1815f2 100644
--- a/chrome/browser/extensions/extension_metrics_module.cc
+++ b/chrome/browser/extensions/extension_metrics_module.cc
@@ -4,11 +4,14 @@
 
 #include "chrome/browser/extensions/extension_metrics_module.h"
 
+#include "base/metrics/histogram.h"
 #include "base/values.h"
-#include "base/histogram.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/browser/metrics/user_metrics.h"
 
+using base::Histogram;
+using base::LinearHistogram;
+
 namespace {
 
 // Build the full name of a metrics for the given extension.  Each metric
diff --git a/chrome/browser/extensions/extension_metrics_module.h b/chrome/browser/extensions/extension_metrics_module.h
index f7a91dc..523acc0 100644
--- a/chrome/browser/extensions/extension_metrics_module.h
+++ b/chrome/browser/extensions/extension_metrics_module.h
@@ -8,7 +8,7 @@
 
 #include <string>
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "chrome/browser/extensions/extension_function.h"
 
 class MetricsRecordUserActionFunction : public SyncExtensionFunction {
@@ -19,8 +19,9 @@ class MetricsRecordUserActionFunction : public SyncExtensionFunction {
 class MetricsHistogramHelperFunction : public SyncExtensionFunction {
  protected:
   bool GetNameAndSample(std::string* name, int* sample);
-  virtual bool RecordValue(const std::string& name, Histogram::ClassType type,
-      int min, int max, size_t buckets, int sample);
+  virtual bool RecordValue(const std::string& name,
+                           base::Histogram::ClassType type,
+                           int min, int max, size_t buckets, int sample);
 };
 
 class MetricsRecordValueFunction : public MetricsHistogramHelperFunction {
diff --git a/chrome/browser/extensions/extension_updater.cc b/chrome/browser/extensions/extension_updater.cc
index da669c6..52a4b4fe 100644
--- a/chrome/browser/extensions/extension_updater.cc
+++ b/chrome/browser/extensions/extension_updater.cc
@@ -9,7 +9,7 @@
 
 #include "base/logging.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/rand_util.h"
 #include "base/sha2.h"
 #include "base/stl_util-inl.h"
diff --git a/chrome/browser/extensions/extensions_service.cc b/chrome/browser/extensions/extensions_service.cc
index 693779b7..3c65525 100644
--- a/chrome/browser/extensions/extensions_service.cc
+++ b/chrome/browser/extensions/extensions_service.cc
@@ -9,7 +9,7 @@
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/stl_util-inl.h"
 #include "base/string16.h"
 #include "base/string_number_conversions.h"
diff --git a/chrome/browser/gtk/download_item_gtk.cc b/chrome/browser/gtk/download_item_gtk.cc
index 5da78ca1..63d3093 100644
--- a/chrome/browser/gtk/download_item_gtk.cc
+++ b/chrome/browser/gtk/download_item_gtk.cc
@@ -10,7 +10,7 @@
 #include "app/text_elider.h"
 #include "base/basictypes.h"
 #include "base/callback.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
diff --git a/chrome/browser/gtk/external_protocol_dialog_gtk.cc b/chrome/browser/gtk/external_protocol_dialog_gtk.cc
index 2819fbb..f59a26e 100644
--- a/chrome/browser/gtk/external_protocol_dialog_gtk.cc
+++ b/chrome/browser/gtk/external_protocol_dialog_gtk.cc
@@ -9,7 +9,7 @@
 #include <string>
 
 #include "app/l10n_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/message_loop.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
diff --git a/chrome/browser/history/history_backend.cc b/chrome/browser/history/history_backend.cc
index 286ddb5..4b37ccd 100644
--- a/chrome/browser/history/history_backend.cc
+++ b/chrome/browser/history/history_backend.cc
@@ -9,7 +9,7 @@
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/message_loop.h"
 #include "base/scoped_ptr.h"
 #include "base/scoped_vector.h"
diff --git a/chrome/browser/history/history_database.cc b/chrome/browser/history/history_database.cc
index 4661814..56ee054 100644
--- a/chrome/browser/history/history_database.cc
+++ b/chrome/browser/history/history_database.cc
@@ -13,7 +13,7 @@
 #if defined(OS_MACOSX)
 #include "base/mac_util.h"
 #endif
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/rand_util.h"
 #include "base/string_util.h"
 #include "chrome/browser/diagnostics/sqlite_diagnostics.h"
diff --git a/chrome/browser/history/in_memory_database.cc b/chrome/browser/history/in_memory_database.cc
index a6a9a6f..3227a7a 100644
--- a/chrome/browser/history/in_memory_database.cc
+++ b/chrome/browser/history/in_memory_database.cc
@@ -5,8 +5,8 @@
 #include "chrome/browser/history/in_memory_database.h"
 
 #include "base/file_path.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "build/build_config.h"
diff --git a/chrome/browser/history/in_memory_history_backend.cc b/chrome/browser/history/in_memory_history_backend.cc
index 7084aa1..6827a78 100644
--- a/chrome/browser/history/in_memory_history_backend.cc
+++ b/chrome/browser/history/in_memory_history_backend.cc
@@ -5,7 +5,7 @@
 #include "chrome/browser/history/in_memory_history_backend.h"
 
 #include "base/command_line.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
diff --git a/chrome/browser/history/text_database.cc b/chrome/browser/history/text_database.cc
index 71c801f..7454681 100644
--- a/chrome/browser/history/text_database.cc
+++ b/chrome/browser/history/text_database.cc
@@ -11,8 +11,8 @@
 #include "app/sql/statement.h"
 #include "app/sql/transaction.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
diff --git a/chrome/browser/history/text_database_manager.cc b/chrome/browser/history/text_database_manager.cc
index 99f068ea..c23158e 100644
--- a/chrome/browser/history/text_database_manager.cc
+++ b/chrome/browser/history/text_database_manager.cc
@@ -6,7 +6,7 @@
 
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/string_util.h"
diff --git a/chrome/browser/jankometer.cc b/chrome/browser/jankometer.cc
index e1ac790..a9a99b0 100644
--- a/chrome/browser/jankometer.cc
+++ b/chrome/browser/jankometer.cc
@@ -8,10 +8,10 @@
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/stats_counters.h"
 #include "base/ref_counted.h"
-#include "base/stats_counters.h"
 #include "base/string_util.h"
 #include "base/thread.h"
 #include "base/time.h"
@@ -102,10 +102,10 @@ class JankObserverHelper {
   TimeDelta queueing_time_;
 
   // Counters for the two types of jank we measure.
-  StatsCounter slow_processing_counter_;  // Messages with long processing time.
-  StatsCounter queueing_delay_counter_;   // Messages with long queueing delay.
-  scoped_refptr<Histogram> process_times_;  // Time spent processing task.
-  scoped_refptr<Histogram> total_times_;  // Total queueing plus processing.
+  base::StatsCounter slow_processing_counter_;  // Msgs w/ long proc time.
+  base::StatsCounter queueing_delay_counter_;   // Msgs w/ long queueing delay.
+  scoped_refptr<base::Histogram> process_times_;  // Time spent proc. task.
+  scoped_refptr<base::Histogram> total_times_;  // Total queueing plus proc.
   JankWatchdog total_time_watchdog_;  // Watching for excessive total_time.
 
   DISALLOW_COPY_AND_ASSIGN(JankObserverHelper);
@@ -119,12 +119,12 @@ JankObserverHelper::JankObserverHelper(
       slow_processing_counter_(std::string("Chrome.SlowMsg") + thread_name),
       queueing_delay_counter_(std::string("Chrome.DelayMsg") + thread_name),
       total_time_watchdog_(excessive_duration, thread_name, watchdog_enable) {
-  process_times_ = Histogram::FactoryGet(
+  process_times_ = base::Histogram::FactoryGet(
       std::string("Chrome.ProcMsgL ") + thread_name,
-      1, 3600000, 50, Histogram::kUmaTargetedHistogramFlag);
-  total_times_ = Histogram::FactoryGet(
+      1, 3600000, 50, base::Histogram::kUmaTargetedHistogramFlag);
+  total_times_ = base::Histogram::FactoryGet(
       std::string("Chrome.TotalMsgL ") + thread_name,
-      1, 3600000, 50, Histogram::kUmaTargetedHistogramFlag);
+      1, 3600000, 50, base::Histogram::kUmaTargetedHistogramFlag);
 }
 
 JankObserverHelper::~JankObserverHelper() {}
diff --git a/chrome/browser/memory_details.cc b/chrome/browser/memory_details.cc
index 5bfbf1a..6c1ea77 100644
--- a/chrome/browser/memory_details.cc
+++ b/chrome/browser/memory_details.cc
@@ -5,7 +5,7 @@
 #include "chrome/browser/memory_details.h"
 
 #include "base/file_version_info.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/process_util.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
diff --git a/chrome/browser/metrics/histogram_synchronizer.cc b/chrome/browser/metrics/histogram_synchronizer.cc
index 288d552..3311bb5 100644
--- a/chrome/browser/metrics/histogram_synchronizer.cc
+++ b/chrome/browser/metrics/histogram_synchronizer.cc
@@ -4,7 +4,7 @@
 
 #include "chrome/browser/metrics/histogram_synchronizer.h"
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/logging.h"
 #include "base/thread.h"
 #include "chrome/browser/browser_thread.h"
@@ -140,7 +140,7 @@ void HistogramSynchronizer::DeserializeHistogramList(
   for (std::vector<std::string>::const_iterator it = histograms.begin();
        it < histograms.end();
        ++it) {
-    Histogram::DeserializeHistogramInfo(*it);
+    base::Histogram::DeserializeHistogramInfo(*it);
   }
 
   // Record that we have received a histogram from renderer process.
diff --git a/chrome/browser/metrics/metrics_service.cc b/chrome/browser/metrics/metrics_service.cc
index e4c9a12..2687eba 100644
--- a/chrome/browser/metrics/metrics_service.cc
+++ b/chrome/browser/metrics/metrics_service.cc
@@ -160,8 +160,8 @@
 
 #include "base/base64.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/md5.h"
+#include "base/metrics/histogram.h"
 #include "base/rand_util.h"
 #include "base/string_number_conversions.h"
 #include "base/thread.h"
diff --git a/chrome/browser/net/preconnect.cc b/chrome/browser/net/preconnect.cc
index a799f66..6780ade 100644
--- a/chrome/browser/net/preconnect.cc
+++ b/chrome/browser/net/preconnect.cc
@@ -4,8 +4,8 @@
 
 #include "chrome/browser/net/preconnect.h"
 
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/browser_thread.h"
diff --git a/chrome/browser/net/predictor.cc b/chrome/browser/net/predictor.cc
index 10b19a4..fd55d2f 100644
--- a/chrome/browser/net/predictor.cc
+++ b/chrome/browser/net/predictor.cc
@@ -9,8 +9,7 @@
 #include <sstream>
 
 #include "base/compiler_specific.h"
-#include "base/histogram.h"
-#include "base/stats_counters.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/time.h"
 #include "base/values.h"
diff --git a/chrome/browser/net/predictor_api.cc b/chrome/browser/net/predictor_api.cc
index 23f54f0..a1270dc 100644
--- a/chrome/browser/net/predictor_api.cc
+++ b/chrome/browser/net/predictor_api.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -7,8 +7,8 @@
 #include <map>
 #include <string>
 
+#include "base/metrics/field_trial.h"
 #include "base/singleton.h"
-#include "base/stats_counters.h"
 #include "base/stl_util-inl.h"
 #include "base/string_number_conversions.h"
 #include "base/thread.h"
@@ -506,11 +506,11 @@ PredictorInit::PredictorInit(PrefService* user_prefs,
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // Set up a field trial to see what disabling DNS pre-resolution does to
   // latency of page loads.
-  FieldTrial::Probability kDivisor = 1000;
+  base::FieldTrial::Probability kDivisor = 1000;
   // For each option (i.e., non-default), we have a fixed probability.
-  FieldTrial::Probability kProbabilityPerGroup = 1;  // 0.1% probability.
+  base::FieldTrial::Probability kProbabilityPerGroup = 1;  // 0.1% probability.
 
-  trial_ = new FieldTrial("DnsImpact", kDivisor);
+  trial_ = new base::FieldTrial("DnsImpact", kDivisor);
 
   // First option is to disable prefetching completely.
   int disabled_prefetch = trial_->AppendGroup("disabled_prefetch",
@@ -546,7 +546,7 @@ PredictorInit::PredictorInit(PrefService* user_prefs,
       "max_6 concurrent_prefetch", kProbabilityPerGroup);
 
   trial_->AppendGroup("default_enabled_prefetch",
-      FieldTrial::kAllRemainingProbability);
+      base::FieldTrial::kAllRemainingProbability);
 
   // We will register the incognito observer regardless of whether prefetching
   // is enabled, as it is also used to clear the host cache.
@@ -585,5 +585,7 @@ PredictorInit::PredictorInit(PrefService* user_prefs,
   }
 }
 
+PredictorInit::~PredictorInit() {
+}
 
 }  // namespace chrome_browser_net
diff --git a/chrome/browser/net/predictor_api.h b/chrome/browser/net/predictor_api.h
index 062a2a6..3e04e11 100644
--- a/chrome/browser/net/predictor_api.h
+++ b/chrome/browser/net/predictor_api.h
@@ -16,11 +16,14 @@
 #include <string>
 #include <vector>
 
-#include "base/field_trial.h"
 #include "base/ref_counted.h"
 #include "chrome/browser/autocomplete/autocomplete.h"
 #include "chrome/browser/net/predictor.h"
 
+namespace base {
+class FieldTrial;
+}
+
 class PrefService;
 
 namespace chrome_browser_net {
@@ -90,10 +93,11 @@ class PredictorInit {
 
   PredictorInit(PrefService* user_prefs, PrefService* local_state,
                 bool preconnect_enabled);
+  ~PredictorInit();
 
  private:
   // Maintain a field trial instance when we do A/B testing.
-  scoped_refptr<FieldTrial> trial_;
+  scoped_refptr<base::FieldTrial> trial_;
 
   DISALLOW_COPY_AND_ASSIGN(PredictorInit);
 };
diff --git a/chrome/browser/net/sqlite_persistent_cookie_store.cc b/chrome/browser/net/sqlite_persistent_cookie_store.cc
index 83fa6fd..003c302 100644
--- a/chrome/browser/net/sqlite_persistent_cookie_store.cc
+++ b/chrome/browser/net/sqlite_persistent_cookie_store.cc
@@ -10,8 +10,8 @@
 #include "app/sql/transaction.h"
 #include "base/basictypes.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
 #include "base/string_util.h"
diff --git a/chrome/browser/net/url_info.cc b/chrome/browser/net/url_info.cc
index 994cfe7..cbf35db 100644
--- a/chrome/browser/net/url_info.cc
+++ b/chrome/browser/net/url_info.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -9,10 +9,9 @@
 #include <algorithm>
 #include <string>
 
-#include "base/field_trial.h"
 #include "base/format_macros.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 
 using base::Time;
@@ -110,9 +109,10 @@ void UrlInfo::RemoveFromQueue() {
   }
   // Make a custom linear histogram for the region from 0 to boundary.
   const size_t kBucketCount = 52;
-  static scoped_refptr<Histogram> histogram = LinearHistogram::FactoryTimeGet(
-      "DNS.QueueRecycledUnder2", TimeDelta(), kBoundary, kBucketCount,
-      Histogram::kUmaTargetedHistogramFlag);
+  static scoped_refptr<base::Histogram> histogram =
+      base::LinearHistogram::FactoryTimeGet(
+          "DNS.QueueRecycledUnder2", TimeDelta(), kBoundary, kBucketCount,
+          base::Histogram::kUmaTargetedHistogramFlag);
   histogram->AddTime(queue_duration_);
 }
 
diff --git a/chrome/browser/net/websocket_experiment/websocket_experiment_runner.cc b/chrome/browser/net/websocket_experiment/websocket_experiment_runner.cc
index 692d4d0..e09febc 100644
--- a/chrome/browser/net/websocket_experiment/websocket_experiment_runner.cc
+++ b/chrome/browser/net/websocket_experiment/websocket_experiment_runner.cc
@@ -6,8 +6,8 @@
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
-#include "base/field_trial.h"
 #include "base/message_loop.h"
+#include "base/metrics/field_trial.h"
 #include "base/task.h"
 #include "base/string_util.h"
 #include "chrome/browser/browser_thread.h"
@@ -28,10 +28,12 @@ static scoped_refptr<WebSocketExperimentRunner> runner;
 void WebSocketExperimentRunner::Start() {
   DCHECK(!runner.get());
 
-  scoped_refptr<FieldTrial> trial = new FieldTrial("WebSocketExperiment", 1000);
+  scoped_refptr<base::FieldTrial> trial =
+      new base::FieldTrial("WebSocketExperiment", 1000);
   trial->AppendGroup("active", 5);  // 0.5% in active group.
 
-  bool run_experiment = (trial->group() != FieldTrial::kNotParticipating);
+  bool run_experiment =
+      (trial->group() != base::FieldTrial::kNotParticipating);
 #ifndef NDEBUG
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
   std::string experiment_host = command_line.GetSwitchValueASCII(
diff --git a/chrome/browser/net/websocket_experiment/websocket_experiment_runner.h b/chrome/browser/net/websocket_experiment/websocket_experiment_runner.h
index 16b20f0..785b5cf 100644
--- a/chrome/browser/net/websocket_experiment/websocket_experiment_runner.h
+++ b/chrome/browser/net/websocket_experiment/websocket_experiment_runner.h
@@ -16,7 +16,6 @@
 #pragma once
 
 #include "base/basictypes.h"
-#include "base/histogram.h"
 #include "base/linked_ptr.h"
 #include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
diff --git a/chrome/browser/net/websocket_experiment/websocket_experiment_task.cc b/chrome/browser/net/websocket_experiment/websocket_experiment_task.cc
index cc7929c..6279615 100644
--- a/chrome/browser/net/websocket_experiment/websocket_experiment_task.cc
+++ b/chrome/browser/net/websocket_experiment/websocket_experiment_task.cc
@@ -5,7 +5,7 @@
 #include "chrome/browser/net/websocket_experiment/websocket_experiment_task.h"
 
 #include "base/hash_tables.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/profile.h"
 #include "chrome/common/net/url_request_context_getter.h"
@@ -14,6 +14,9 @@
 #include "net/base/net_errors.h"
 #include "net/websockets/websocket.h"
 
+using base::Histogram;
+using base::LinearHistogram;
+
 namespace chrome_browser_net_websocket_experiment {
 
 static std::string GetProtocolVersionName(
diff --git a/chrome/browser/notifications/desktop_notification_service.cc b/chrome/browser/notifications/desktop_notification_service.cc
index 4df30e9..351485f 100644
--- a/chrome/browser/notifications/desktop_notification_service.cc
+++ b/chrome/browser/notifications/desktop_notification_service.cc
@@ -6,7 +6,7 @@
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/thread.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_child_process_host.h"
diff --git a/chrome/browser/omnibox_search_hint.cc b/chrome/browser/omnibox_search_hint.cc
index 1a91efe..e1ab84c 100644
--- a/chrome/browser/omnibox_search_hint.cc
+++ b/chrome/browser/omnibox_search_hint.cc
@@ -7,7 +7,7 @@
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/task.h"
 #include "chrome/browser/autocomplete/autocomplete_edit.h"
 #include "chrome/browser/autocomplete/autocomplete_edit_view.h"
diff --git a/chrome/browser/password_manager/login_database.cc b/chrome/browser/password_manager/login_database.cc
index 700dd3f..a7c26b4 100644
--- a/chrome/browser/password_manager/login_database.cc
+++ b/chrome/browser/password_manager/login_database.cc
@@ -11,8 +11,8 @@
 #include "app/sql/transaction.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 
diff --git a/chrome/browser/password_manager/password_form_manager.cc b/chrome/browser/password_manager/password_form_manager.cc
index e268317..977806d 100644
--- a/chrome/browser/password_manager/password_form_manager.cc
+++ b/chrome/browser/password_manager/password_form_manager.cc
@@ -6,7 +6,7 @@
 
 #include <algorithm>
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
 #include "chrome/browser/password_manager/password_manager.h"
diff --git a/chrome/browser/prefs/pref_service.cc b/chrome/browser/prefs/pref_service.cc
index eb1e0e3..80b3d38 100644
--- a/chrome/browser/prefs/pref_service.cc
+++ b/chrome/browser/prefs/pref_service.cc
@@ -11,9 +11,9 @@
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/stl_util-inl.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
diff --git a/chrome/browser/profile_impl.cc b/chrome/browser/profile_impl.cc
index e2ea94a..491008c 100644
--- a/chrome/browser/profile_impl.cc
+++ b/chrome/browser/profile_impl.cc
@@ -9,7 +9,7 @@
 #include "base/environment.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/scoped_ptr.h"
 #include "base/string_number_conversions.h"
diff --git a/chrome/browser/renderer_host/audio_renderer_host.cc b/chrome/browser/renderer_host/audio_renderer_host.cc
index af63515..9493799 100644
--- a/chrome/browser/renderer_host/audio_renderer_host.cc
+++ b/chrome/browser/renderer_host/audio_renderer_host.cc
@@ -4,8 +4,8 @@
 
 #include "chrome/browser/renderer_host/audio_renderer_host.h"
 
-#include "base/histogram.h"
 #include "base/lock.h"
+#include "base/metrics/histogram.h"
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "base/sys_info.h"
diff --git a/chrome/browser/renderer_host/backing_store_x.cc b/chrome/browser/renderer_host/backing_store_x.cc
index f2704c8..a79a8fc 100644
--- a/chrome/browser/renderer_host/backing_store_x.cc
+++ b/chrome/browser/renderer_host/backing_store_x.cc
@@ -22,8 +22,8 @@
 #include "app/x11_util.h"
 #include "app/x11_util_internal.h"
 #include "base/compiler_specific.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "chrome/browser/renderer_host/render_process_host.h"
 #include "gfx/rect.h"
diff --git a/chrome/browser/renderer_host/browser_render_process_host.cc b/chrome/browser/renderer_host/browser_render_process_host.cc
index 4c152e06..65172c8 100644
--- a/chrome/browser/renderer_host/browser_render_process_host.cc
+++ b/chrome/browser/renderer_host/browser_render_process_host.cc
@@ -17,9 +17,9 @@
 
 #include "app/app_switches.h"
 #include "base/command_line.h"
-#include "base/field_trial.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
 #include "base/platform_file.h"
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
@@ -490,11 +490,11 @@ void BrowserRenderProcessHost::AppendRendererCommandLine(
   const std::string locale = g_browser_process->GetApplicationLocale();
   command_line->AppendSwitchASCII(switches::kLang, locale);
 
-  // If we run FieldTrials, we want to pass to their state to the renderer so
+  // If we run base::FieldTrials, we want to pass to their state to the renderer so
   // that it can act in accordance with each state, or record histograms
-  // relating to the FieldTrial states.
+  // relating to the base::FieldTrial states.
   std::string field_trial_states;
-  FieldTrialList::StatesToString(&field_trial_states);
+  base::FieldTrialList::StatesToString(&field_trial_states);
   if (!field_trial_states.empty()) {
     command_line->AppendSwitchASCII(switches::kForceFieldTestNameAndValue,
                                     field_trial_states);
diff --git a/chrome/browser/renderer_host/buffered_resource_handler.cc b/chrome/browser/renderer_host/buffered_resource_handler.cc
index 78389f0..a19d3c3 100644
--- a/chrome/browser/renderer_host/buffered_resource_handler.cc
+++ b/chrome/browser/renderer_host/buffered_resource_handler.cc
@@ -6,8 +6,8 @@
 
 #include <vector>
 
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/renderer_host/download_throttling_resource_handler.h"
@@ -29,19 +29,21 @@ namespace {
 void RecordSnifferMetrics(bool sniffing_blocked,
                           bool we_would_like_to_sniff,
                           const std::string& mime_type) {
-  static scoped_refptr<Histogram> nosniff_usage = BooleanHistogram::FactoryGet(
-      "nosniff.usage", Histogram::kUmaTargetedHistogramFlag);
+  static scoped_refptr<base::Histogram> nosniff_usage =
+      base::BooleanHistogram::FactoryGet(
+          "nosniff.usage", base::Histogram::kUmaTargetedHistogramFlag);
   nosniff_usage->AddBoolean(sniffing_blocked);
 
   if (sniffing_blocked) {
-    static scoped_refptr<Histogram> nosniff_otherwise =
-        BooleanHistogram::FactoryGet("nosniff.otherwise",
-                                     Histogram::kUmaTargetedHistogramFlag);
+    static scoped_refptr<base::Histogram> nosniff_otherwise =
+        base::BooleanHistogram::FactoryGet(
+            "nosniff.otherwise", base::Histogram::kUmaTargetedHistogramFlag);
     nosniff_otherwise->AddBoolean(we_would_like_to_sniff);
 
-    static scoped_refptr<Histogram> nosniff_empty_mime_type =
-        BooleanHistogram::FactoryGet("nosniff.empty_mime_type",
-                                     Histogram::kUmaTargetedHistogramFlag);
+    static scoped_refptr<base::Histogram> nosniff_empty_mime_type =
+        base::BooleanHistogram::FactoryGet(
+            "nosniff.empty_mime_type",
+            base::Histogram::kUmaTargetedHistogramFlag);
     nosniff_empty_mime_type->AddBoolean(mime_type.empty());
   }
 }
diff --git a/chrome/browser/renderer_host/offline_resource_handler.cc b/chrome/browser/renderer_host/offline_resource_handler.cc
index dafa911..68a036d 100644
--- a/chrome/browser/renderer_host/offline_resource_handler.cc
+++ b/chrome/browser/renderer_host/offline_resource_handler.cc
@@ -6,8 +6,8 @@
 
 #include <vector>
 
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/singleton.h"
 #include "base/string_util.h"
 #include "chrome/browser/browser_thread.h"
diff --git a/chrome/browser/renderer_host/render_view_host.cc b/chrome/browser/renderer_host/render_view_host.cc
index c91671f..3781bed 100644
--- a/chrome/browser/renderer_host/render_view_host.cc
+++ b/chrome/browser/renderer_host/render_view_host.cc
@@ -11,7 +11,7 @@
 #include "base/command_line.h"
 #include "base/i18n/rtl.h"
 #include "base/json/json_reader.h"
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
 #include "base/string_util.h"
 #include "base/time.h"
 #include "base/values.h"
@@ -1145,7 +1145,7 @@ void RenderViewHost::OnMsgDidLoadResourceFromMemoryCache(
     const std::string& frame_origin,
     const std::string& main_frame_origin,
     const std::string& security_info) {
-  static StatsCounter cache("WebKit.CacheHit");
+  static base::StatsCounter cache("WebKit.CacheHit");
   cache.Increment();
 
   RenderViewHostDelegate::Resource* resource_delegate =
diff --git a/chrome/browser/renderer_host/render_widget_host.cc b/chrome/browser/renderer_host/render_widget_host.cc
index 684c7ef..7d4aa79f 100644
--- a/chrome/browser/renderer_host/render_widget_host.cc
+++ b/chrome/browser/renderer_host/render_widget_host.cc
@@ -7,8 +7,8 @@
 #include "app/keyboard_codes.h"
 #include "base/auto_reset.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "chrome/browser/accessibility/browser_accessibility_state.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/renderer_host/backing_store.h"
diff --git a/chrome/browser/renderer_host/render_widget_host_view_gtk.cc b/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
index c69397d..5f4a843 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
+++ b/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
@@ -22,8 +22,8 @@
 #include "app/x11_util.h"
 #include "base/command_line.h"
 #include "base/logging.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
diff --git a/chrome/browser/renderer_host/render_widget_host_view_mac.mm b/chrome/browser/renderer_host/render_widget_host_view_mac.mm
index e6a6ba6..ce0f8c0 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/chrome/browser/renderer_host/render_widget_host_view_mac.mm
@@ -10,8 +10,8 @@
 #include "app/surface/io_surface_support_mac.h"
 #import "base/chrome_application_mac.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #import "base/scoped_nsautorelease_pool.h"
 #import "base/scoped_nsobject.h"
 #include "base/string_util.h"
diff --git a/chrome/browser/renderer_host/render_widget_host_view_views.cc b/chrome/browser/renderer_host/render_widget_host_view_views.cc
index 76f6cd6..25e8a88 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_views.cc
+++ b/chrome/browser/renderer_host/render_widget_host_view_views.cc
@@ -11,9 +11,9 @@
 #include "app/l10n_util.h"
 #include "app/x11_util.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/task.h"
 #include "base/time.h"
diff --git a/chrome/browser/renderer_host/render_widget_host_view_win.cc b/chrome/browser/renderer_host/render_widget_host_view_win.cc
index 29d4174..0b66f0c 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_win.cc
+++ b/chrome/browser/renderer_host/render_widget_host_view_win.cc
@@ -8,8 +8,8 @@
 #include "app/l10n_util_win.h"
 #include "app/resource_bundle.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/i18n/rtl.h"
+#include "base/metrics/histogram.h"
 #include "base/process_util.h"
 #include "base/scoped_comptr_win.h"
 #include "base/thread.h"
diff --git a/chrome/browser/renderer_host/resource_dispatcher_host.cc b/chrome/browser/renderer_host/resource_dispatcher_host.cc
index 3faa6f8..a17b12b7 100644
--- a/chrome/browser/renderer_host/resource_dispatcher_host.cc
+++ b/chrome/browser/renderer_host/resource_dispatcher_host.cc
@@ -10,8 +10,8 @@
 
 #include "base/logging.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/scoped_ptr.h"
 #include "base/shared_memory.h"
 #include "base/stl_util-inl.h"
diff --git a/chrome/browser/renderer_host/resource_message_filter.cc b/chrome/browser/renderer_host/resource_message_filter.cc
index 1351962..d62f6d1 100644
--- a/chrome/browser/renderer_host/resource_message_filter.cc
+++ b/chrome/browser/renderer_host/resource_message_filter.cc
@@ -12,7 +12,7 @@
 #endif
 #include "base/file_util.h"
 #include "base/file_path.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/process_util.h"
 #include "base/shared_memory.h"
 #include "base/thread.h"
diff --git a/chrome/browser/renderer_host/web_cache_manager.cc b/chrome/browser/renderer_host/web_cache_manager.cc
index 04da747..88baa7b 100644
--- a/chrome/browser/renderer_host/web_cache_manager.cc
+++ b/chrome/browser/renderer_host/web_cache_manager.cc
@@ -7,7 +7,7 @@
 #include <algorithm>
 
 #include "base/compiler_specific.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/singleton.h"
 #include "base/sys_info.h"
 #include "base/time.h"
diff --git a/chrome/browser/safe_browsing/protocol_manager.cc b/chrome/browser/safe_browsing/protocol_manager.cc
index 52ccbace..d7ba1a8 100644
--- a/chrome/browser/safe_browsing/protocol_manager.cc
+++ b/chrome/browser/safe_browsing/protocol_manager.cc
@@ -8,8 +8,8 @@
 #include "base/base64.h"
 #endif
 #include "base/environment.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/rand_util.h"
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
diff --git a/chrome/browser/safe_browsing/safe_browsing_database.cc b/chrome/browser/safe_browsing/safe_browsing_database.cc
index 72d2554..df76d47 100644
--- a/chrome/browser/safe_browsing/safe_browsing_database.cc
+++ b/chrome/browser/safe_browsing/safe_browsing_database.cc
@@ -6,12 +6,12 @@
 
 #include "base/command_line.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/stats_counters.h"
 #include "base/time.h"
 #include "base/message_loop.h"
 #include "base/process_util.h"
 #include "base/sha2.h"
-#include "base/stats_counters.h"
 #include "chrome/browser/safe_browsing/bloom_filter.h"
 #include "chrome/browser/safe_browsing/safe_browsing_database_bloom.h"
 #include "chrome/browser/safe_browsing/safe_browsing_store_file.h"
diff --git a/chrome/browser/safe_browsing/safe_browsing_database_bloom.cc b/chrome/browser/safe_browsing/safe_browsing_database_bloom.cc
index 0c636ef..36a03c0 100644
--- a/chrome/browser/safe_browsing/safe_browsing_database_bloom.cc
+++ b/chrome/browser/safe_browsing/safe_browsing_database_bloom.cc
@@ -6,11 +6,11 @@
 
 #include "base/auto_reset.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_counters.h"
 #include "base/process_util.h"
 #include "base/sha2.h"
-#include "base/stats_counters.h"
 #include "base/string_util.h"
 #include "chrome/browser/safe_browsing/bloom_filter.h"
 #include "chrome/common/sqlite_compiled_statement.h"
diff --git a/chrome/browser/safe_browsing/safe_browsing_database_bloom_unittest.cc b/chrome/browser/safe_browsing/safe_browsing_database_bloom_unittest.cc
index 4359cc5..2032efd 100644
--- a/chrome/browser/safe_browsing/safe_browsing_database_bloom_unittest.cc
+++ b/chrome/browser/safe_browsing/safe_browsing_database_bloom_unittest.cc
@@ -11,11 +11,11 @@
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_counters.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/scoped_temp_dir.h"
 #include "base/sha2.h"
-#include "base/stats_counters.h"
 #include "base/string_util.h"
 #include "base/time.h"
 #include "chrome/browser/safe_browsing/protocol_parser.h"
@@ -1093,7 +1093,7 @@ TEST_F(SafeBrowsingDatabaseBloomTest, DISABLED_SqliteCorruptionHandling) {
 namespace {
 
 void PrintStat(const char* name) {
-  int value = StatsTable::current()->GetCounterValue(name);
+  int value = base::StatsTable::current()->GetCounterValue(name);
   SB_DLOG(INFO) << StringPrintf("%s %d", name, value);
 }
 
diff --git a/chrome/browser/safe_browsing/safe_browsing_database_unittest.cc b/chrome/browser/safe_browsing/safe_browsing_database_unittest.cc
index d381d55..6407e53 100644
--- a/chrome/browser/safe_browsing/safe_browsing_database_unittest.cc
+++ b/chrome/browser/safe_browsing/safe_browsing_database_unittest.cc
@@ -10,11 +10,11 @@
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_counters.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/scoped_temp_dir.h"
 #include "base/sha2.h"
-#include "base/stats_counters.h"
 #include "base/string_util.h"
 #include "base/time.h"
 #include "chrome/browser/safe_browsing/protocol_parser.h"
@@ -1168,7 +1168,7 @@ TEST_F(SafeBrowsingDatabaseTest, DISABLED_FileCorruptionHandling) {
 namespace {
 
 void PrintStat(const char* name) {
-  int value = StatsTable::current()->GetCounterValue(name);
+  int value = base::StatsTable::current()->GetCounterValue(name);
   SB_DLOG(INFO) << StringPrintf("%s %d", name, value);
 }
 
diff --git a/chrome/browser/safe_browsing/safe_browsing_store_file.cc b/chrome/browser/safe_browsing/safe_browsing_store_file.cc
index a5cec62..196cf0d 100644
--- a/chrome/browser/safe_browsing/safe_browsing_store_file.cc
+++ b/chrome/browser/safe_browsing/safe_browsing_store_file.cc
@@ -5,7 +5,7 @@
 #include "chrome/browser/safe_browsing/safe_browsing_store_file.h"
 
 #include "base/callback.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/md5.h"
 
 // TODO(shess): Remove after migration.
diff --git a/chrome/browser/safe_browsing/safe_browsing_store_sqlite.cc b/chrome/browser/safe_browsing/safe_browsing_store_sqlite.cc
index 486d6f2..8deeff4 100644
--- a/chrome/browser/safe_browsing/safe_browsing_store_sqlite.cc
+++ b/chrome/browser/safe_browsing/safe_browsing_store_sqlite.cc
@@ -8,7 +8,7 @@
 
 #include "base/callback.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/sqlite_compiled_statement.h"
diff --git a/chrome/browser/sessions/session_backend.cc b/chrome/browser/sessions/session_backend.cc
index 342c1f0..f5a0c39 100644
--- a/chrome/browser/sessions/session_backend.cc
+++ b/chrome/browser/sessions/session_backend.cc
@@ -7,7 +7,7 @@
 #include <limits>
 
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/scoped_vector.h"
 #include "net/base/file_stream.h"
 
diff --git a/chrome/browser/sessions/session_service.cc b/chrome/browser/sessions/session_service.cc
index 542d3e3..a430d56 100644
--- a/chrome/browser/sessions/session_service.cc
+++ b/chrome/browser/sessions/session_service.cc
@@ -10,8 +10,8 @@
 
 #include "base/callback.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/pickle.h"
 #include "base/scoped_vector.h"
 #include "base/thread.h"
diff --git a/chrome/browser/spellchecker_mac.mm b/chrome/browser/spellchecker_mac.mm
index 70db304..91d6f3e 100644
--- a/chrome/browser/spellchecker_mac.mm
+++ b/chrome/browser/spellchecker_mac.mm
@@ -10,8 +10,8 @@
 #import <Cocoa/Cocoa.h>
 
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
-#include "base/histogram.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/common/spellcheck_common.h"
 
diff --git a/chrome/browser/ssl/ssl_blocking_page.cc b/chrome/browser/ssl/ssl_blocking_page.cc
index 9a1ba76..91d87c7 100644
--- a/chrome/browser/ssl/ssl_blocking_page.cc
+++ b/chrome/browser/ssl/ssl_blocking_page.cc
@@ -6,8 +6,8 @@
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
-#include "base/histogram.h"
 #include "base/i18n/rtl.h"
+#include "base/metrics/histogram.h"
 #include "base/string_piece.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
diff --git a/chrome/browser/sync/glue/app_data_type_controller.cc b/chrome/browser/sync/glue/app_data_type_controller.cc
index 8a86b1a..cb6cb54 100644
--- a/chrome/browser/sync/glue/app_data_type_controller.cc
+++ b/chrome/browser/sync/glue/app_data_type_controller.cc
@@ -4,7 +4,7 @@
 
 #include "chrome/browser/sync/glue/app_data_type_controller.h"
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/logging.h"
 #include "base/time.h"
 #include "chrome/browser/browser_thread.h"
diff --git a/chrome/browser/sync/glue/autofill_data_type_controller.cc b/chrome/browser/sync/glue/autofill_data_type_controller.cc
index b7ee19b..8c33872 100644
--- a/chrome/browser/sync/glue/autofill_data_type_controller.cc
+++ b/chrome/browser/sync/glue/autofill_data_type_controller.cc
@@ -2,14 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/histogram.h"
+#include "chrome/browser/sync/glue/autofill_data_type_controller.h"
+
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/task.h"
 #include "base/time.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/sync/glue/autofill_change_processor.h"
-#include "chrome/browser/sync/glue/autofill_data_type_controller.h"
 #include "chrome/browser/sync/glue/autofill_model_associator.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_factory.h"
diff --git a/chrome/browser/sync/glue/bookmark_data_type_controller.cc b/chrome/browser/sync/glue/bookmark_data_type_controller.cc
index 1662d5d..093fc16 100644
--- a/chrome/browser/sync/glue/bookmark_data_type_controller.cc
+++ b/chrome/browser/sync/glue/bookmark_data_type_controller.cc
@@ -2,14 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/histogram.h"
+#include "chrome/browser/sync/glue/bookmark_data_type_controller.h"
+
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/sync/glue/bookmark_change_processor.h"
-#include "chrome/browser/sync/glue/bookmark_data_type_controller.h"
 #include "chrome/browser/sync/glue/bookmark_model_associator.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_factory.h"
diff --git a/chrome/browser/sync/glue/extension_data_type_controller.cc b/chrome/browser/sync/glue/extension_data_type_controller.cc
index 2e3368b..d5b7900 100644
--- a/chrome/browser/sync/glue/extension_data_type_controller.cc
+++ b/chrome/browser/sync/glue/extension_data_type_controller.cc
@@ -4,8 +4,8 @@
 
 #include "chrome/browser/sync/glue/extension_data_type_controller.h"
 
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/profile.h"
diff --git a/chrome/browser/sync/glue/password_data_type_controller.cc b/chrome/browser/sync/glue/password_data_type_controller.cc
index 20d9ef6..095306a 100644
--- a/chrome/browser/sync/glue/password_data_type_controller.cc
+++ b/chrome/browser/sync/glue/password_data_type_controller.cc
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/histogram.h"
+#include "chrome/browser/sync/glue/password_data_type_controller.h"
+
+#include "base/metrics/histogram.h"
 #include "base/logging.h"
 #include "base/task.h"
 #include "base/time.h"
@@ -10,7 +12,6 @@
 #include "chrome/browser/password_manager/password_store.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/sync/glue/password_change_processor.h"
-#include "chrome/browser/sync/glue/password_data_type_controller.h"
 #include "chrome/browser/sync/glue/password_model_associator.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_factory.h"
diff --git a/chrome/browser/sync/glue/preference_data_type_controller.cc b/chrome/browser/sync/glue/preference_data_type_controller.cc
index cb3fc6c7..f714ed1 100644
--- a/chrome/browser/sync/glue/preference_data_type_controller.cc
+++ b/chrome/browser/sync/glue/preference_data_type_controller.cc
@@ -2,12 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/histogram.h"
+#include "chrome/browser/sync/glue/preference_data_type_controller.h"
+
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/sync/glue/preference_change_processor.h"
-#include "chrome/browser/sync/glue/preference_data_type_controller.h"
 #include "chrome/browser/sync/glue/preference_model_associator.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_factory.h"
diff --git a/chrome/browser/sync/glue/session_data_type_controller.cc b/chrome/browser/sync/glue/session_data_type_controller.cc
index 1e2a072..8b68972 100644
--- a/chrome/browser/sync/glue/session_data_type_controller.cc
+++ b/chrome/browser/sync/glue/session_data_type_controller.cc
@@ -2,12 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/histogram.h"
+#include "chrome/browser/sync/glue/session_data_type_controller.h"
+
+#include "base/metrics/histogram.h"
 #include "base/logging.h"
 #include "base/time.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/sync/glue/session_change_processor.h"
-#include "chrome/browser/sync/glue/session_data_type_controller.h"
 #include "chrome/browser/sync/glue/session_model_associator.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_factory.h"
diff --git a/chrome/browser/sync/glue/session_data_type_controller.h b/chrome/browser/sync/glue/session_data_type_controller.h
index 0dc56eb..ae815d4 100644
--- a/chrome/browser/sync/glue/session_data_type_controller.h
+++ b/chrome/browser/sync/glue/session_data_type_controller.h
@@ -11,6 +11,7 @@
 #include "base/basictypes.h"
 #include "base/scoped_ptr.h"
 #include "chrome/browser/sync/glue/data_type_controller.h"
+#include "chrome/browser/sync/glue/session_model_associator.h"
 
 class ProfileSyncFactory;
 class ProfileSyncService;
diff --git a/chrome/browser/sync/glue/theme_data_type_controller.cc b/chrome/browser/sync/glue/theme_data_type_controller.cc
index ecad426..03cf3cd 100644
--- a/chrome/browser/sync/glue/theme_data_type_controller.cc
+++ b/chrome/browser/sync/glue/theme_data_type_controller.cc
@@ -2,13 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/histogram.h"
+#include "chrome/browser/sync/glue/theme_data_type_controller.h"
+
+#include "base/metrics/histogram.h"
 #include "base/logging.h"
 #include "base/time.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/sync/glue/theme_change_processor.h"
-#include "chrome/browser/sync/glue/theme_data_type_controller.h"
 #include "chrome/browser/sync/glue/theme_model_associator.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_factory.h"
diff --git a/chrome/browser/sync/glue/typed_url_data_type_controller.cc b/chrome/browser/sync/glue/typed_url_data_type_controller.cc
index ca9f5cd..6fca194 100644
--- a/chrome/browser/sync/glue/typed_url_data_type_controller.cc
+++ b/chrome/browser/sync/glue/typed_url_data_type_controller.cc
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/histogram.h"
+#include "chrome/browser/sync/glue/typed_url_data_type_controller.h"
+
+#include "base/metrics/histogram.h"
 #include "base/logging.h"
 #include "base/task.h"
 #include "base/time.h"
@@ -10,7 +12,6 @@
 #include "chrome/browser/history/history.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/sync/glue/typed_url_change_processor.h"
-#include "chrome/browser/sync/glue/typed_url_data_type_controller.h"
 #include "chrome/browser/sync/glue/typed_url_model_associator.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_factory.h"
diff --git a/chrome/browser/sync/glue/typed_url_data_type_controller.h b/chrome/browser/sync/glue/typed_url_data_type_controller.h
index db28208..0301135 100644
--- a/chrome/browser/sync/glue/typed_url_data_type_controller.h
+++ b/chrome/browser/sync/glue/typed_url_data_type_controller.h
@@ -23,6 +23,10 @@ class Profile;
 class ProfileSyncFactory;
 class ProfileSyncService;
 
+namespace history {
+class HistoryBackend;
+}
+
 namespace browser_sync {
 
 class AssociatorInterface;
diff --git a/chrome/browser/sync/profile_sync_service.cc b/chrome/browser/sync/profile_sync_service.cc
index bad0859..ddaff62 100644
--- a/chrome/browser/sync/profile_sync_service.cc
+++ b/chrome/browser/sync/profile_sync_service.cc
@@ -10,8 +10,8 @@
 #include "app/l10n_util.h"
 #include "base/callback.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/stl_util-inl.h"
 #include "base/string16.h"
 #include "base/string_util.h"
diff --git a/chrome/browser/sync/sync_setup_flow.cc b/chrome/browser/sync/sync_setup_flow.cc
index 0f22e8c..9cef9768 100644
--- a/chrome/browser/sync/sync_setup_flow.cc
+++ b/chrome/browser/sync/sync_setup_flow.cc
@@ -6,9 +6,9 @@
 
 #include "app/gfx/font_util.h"
 #include "base/callback.h"
-#include "base/histogram.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
diff --git a/chrome/browser/sync/syncable/directory_backing_store.cc b/chrome/browser/sync/syncable/directory_backing_store.cc
index abba0a6..c0036d3 100644
--- a/chrome/browser/sync/syncable/directory_backing_store.cc
+++ b/chrome/browser/sync/syncable/directory_backing_store.cc
@@ -14,8 +14,8 @@
 
 #include "base/file_util.h"
 #include "base/hash_tables.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/stl_util-inl.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
diff --git a/chrome/browser/tab_contents/render_view_context_menu.cc b/chrome/browser/tab_contents/render_view_context_menu.cc
index 1b5af98..4dc7b11 100644
--- a/chrome/browser/tab_contents/render_view_context_menu.cc
+++ b/chrome/browser/tab_contents/render_view_context_menu.cc
@@ -9,8 +9,8 @@
 
 #include "app/l10n_util.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
 #include "base/time.h"
diff --git a/chrome/browser/tab_contents/tab_contents.cc b/chrome/browser/tab_contents/tab_contents.cc
index ebf4756..0ed29a0 100644
--- a/chrome/browser/tab_contents/tab_contents.cc
+++ b/chrome/browser/tab_contents/tab_contents.cc
@@ -14,8 +14,8 @@
 #include "app/text_elider.h"
 #include "base/auto_reset.h"
 #include "base/file_version_info.h"
-#include "base/histogram.h"
 #include "base/i18n/rtl.h"
+#include "base/metrics/histogram.h"
 #include "base/process_util.h"
 #include "base/string16.h"
 #include "base/string_util.h"
diff --git a/chrome/browser/tab_contents/thumbnail_generator.cc b/chrome/browser/tab_contents/thumbnail_generator.cc
index 4d5826a..520faf4 100644
--- a/chrome/browser/tab_contents/thumbnail_generator.cc
+++ b/chrome/browser/tab_contents/thumbnail_generator.cc
@@ -7,7 +7,7 @@
 #include <algorithm>
 #include <map>
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "build/build_config.h"
 #include "chrome/browser/renderer_host/backing_store.h"
diff --git a/chrome/browser/translate/languages_menu_model.cc b/chrome/browser/translate/languages_menu_model.cc
index 93bd100..544410e 100644
--- a/chrome/browser/translate/languages_menu_model.cc
+++ b/chrome/browser/translate/languages_menu_model.cc
@@ -4,7 +4,7 @@
 
 #include "chrome/browser/translate/languages_menu_model.h"
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "chrome/browser/translate/translate_infobar_delegate.h"
 
 LanguagesMenuModel::LanguagesMenuModel(
diff --git a/chrome/browser/translate/options_menu_model.cc b/chrome/browser/translate/options_menu_model.cc
index 56b707b..bb5b157 100644
--- a/chrome/browser/translate/options_menu_model.cc
+++ b/chrome/browser/translate/options_menu_model.cc
@@ -5,7 +5,7 @@
 #include "chrome/browser/translate/options_menu_model.h"
 
 #include "app/l10n_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "chrome/app/chrome_dll_resource.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profile.h"
diff --git a/chrome/browser/translate/translate_infobar_delegate.cc b/chrome/browser/translate/translate_infobar_delegate.cc
index af73d11..6b27cd5 100644
--- a/chrome/browser/translate/translate_infobar_delegate.cc
+++ b/chrome/browser/translate/translate_infobar_delegate.cc
@@ -8,7 +8,7 @@
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
diff --git a/chrome/browser/translate/translate_manager.cc b/chrome/browser/translate/translate_manager.cc
index df5db9e..b948a25 100644
--- a/chrome/browser/translate/translate_manager.cc
+++ b/chrome/browser/translate/translate_manager.cc
@@ -7,7 +7,7 @@
 #include "app/resource_bundle.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
 #include "chrome/browser/browser.h"
diff --git a/chrome/browser/views/download_item_view.cc b/chrome/browser/views/download_item_view.cc
index 1f753e9..ebaa8916 100644
--- a/chrome/browser/views/download_item_view.cc
+++ b/chrome/browser/views/download_item_view.cc
@@ -11,8 +11,8 @@
 #include "app/text_elider.h"
 #include "base/callback.h"
 #include "base/file_path.h"
-#include "base/histogram.h"
 #include "base/i18n/rtl.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 #include "base/utf_string_conversions.h"
diff --git a/chrome/browser/views/external_protocol_dialog.cc b/chrome/browser/views/external_protocol_dialog.cc
index 9546f25..6dda2e3 100644
--- a/chrome/browser/views/external_protocol_dialog.cc
+++ b/chrome/browser/views/external_protocol_dialog.cc
@@ -6,7 +6,7 @@
 
 #include "app/l10n_util.h"
 #include "app/message_box_flags.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/registry.h"
 #include "base/string_util.h"
 #include "base/thread.h"
diff --git a/chrome/browser/views/task_manager_view.cc b/chrome/browser/views/task_manager_view.cc
index 452c5d9..a4d74c2 100644
--- a/chrome/browser/views/task_manager_view.cc
+++ b/chrome/browser/views/task_manager_view.cc
@@ -7,7 +7,7 @@
 #include "app/l10n_util.h"
 #include "app/table_model_observer.h"
 #include "base/command_line.h"
-#include "base/stats_table.h"
+#include "base/metrics/stats_table.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/app/chrome_dll_resource.h"
 #include "chrome/browser/browser_list.h"
@@ -384,7 +384,7 @@ void TaskManagerView::Init() {
 }
 
 void TaskManagerView::UpdateStatsCounters() {
-  StatsTable* stats = StatsTable::current();
+  base::StatsTable* stats = base::StatsTable::current();
   if (stats != NULL) {
     int max = stats->GetMaxCounters();
     // skip the first row (it's header data)
diff --git a/chrome/common/child_process_host.cc b/chrome/common/child_process_host.cc
index 318312a..b001eff 100644
--- a/chrome/common/child_process_host.cc
+++ b/chrome/common/child_process_host.cc
@@ -5,7 +5,7 @@
 #include "chrome/common/child_process_host.h"
 
 #include "base/command_line.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "chrome/common/child_process_info.h"
 #include "chrome/common/chrome_constants.h"
diff --git a/chrome/common/chrome_counters.cc b/chrome/common/chrome_counters.cc
index fea0906..91ebf55 100644
--- a/chrome/common/chrome_counters.cc
+++ b/chrome/common/chrome_counters.cc
@@ -1,13 +1,16 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/chrome_counters.h"
 
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
 
 namespace chrome {
 
+using base::StatsCounterTimer;
+using base::StatsRate;
+
 // Note: We use the construct-on-first-use pattern here, because we don't
 //       want to fight with any static initializer ordering problems later.
 //       The downside of this is that the objects don't ever get cleaned up.
diff --git a/chrome/common/chrome_counters.h b/chrome/common/chrome_counters.h
index e655b83..e53d5b2 100644
--- a/chrome/common/chrome_counters.h
+++ b/chrome/common/chrome_counters.h
@@ -8,31 +8,33 @@
 #define CHROME_COMMON_CHROME_COUNTERS_H_
 #pragma once
 
+namespace base {
 class StatsCounter;
 class StatsCounterTimer;
 class StatsRate;
+}
 
 namespace chrome {
 
 class Counters {
  public:
   // The amount of time spent in chrome initialization.
-  static StatsCounterTimer& chrome_main();
+  static base::StatsCounterTimer& chrome_main();
 
   // The amount of time spent in renderer initialization.
-  static StatsCounterTimer& renderer_main();
+  static base::StatsCounterTimer& renderer_main();
 
   // Time spent in spellchecker initialization.
-  static StatsCounterTimer& spellcheck_init();
+  static base::StatsCounterTimer& spellcheck_init();
 
   // Time/Count of spellcheck lookups.
-  static StatsRate& spellcheck_lookup();
+  static base::StatsRate& spellcheck_lookup();
 
   // Time spent loading the Chrome plugins.
-  static StatsCounterTimer& plugin_load();
+  static base::StatsCounterTimer& plugin_load();
 
   // Time/Count of plugin network interception.
-  static StatsRate& plugin_intercept();
+  static base::StatsRate& plugin_intercept();
 };
 
 }  // namespace chrome
diff --git a/chrome/common/chrome_plugin_lib.cc b/chrome/common/chrome_plugin_lib.cc
index 2b78ed25c..5d1264b 100644
--- a/chrome/common/chrome_plugin_lib.cc
+++ b/chrome/common/chrome_plugin_lib.cc
@@ -6,8 +6,8 @@
 
 #include "base/command_line.h"
 #include "base/hash_tables.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/perftimer.h"
 #include "base/thread.h"
diff --git a/chrome/common/metrics_helpers.cc b/chrome/common/metrics_helpers.cc
index b0fdac1..4fb11b7 100644
--- a/chrome/common/metrics_helpers.cc
+++ b/chrome/common/metrics_helpers.cc
@@ -27,6 +27,8 @@
 
 #define OPEN_ELEMENT_FOR_SCOPE(name) ScopedElement scoped_element(this, name)
 
+using base::Histogram;
+using base::StatisticsRecorder;
 using base::Time;
 using base::TimeDelta;
 
diff --git a/chrome/common/metrics_helpers.h b/chrome/common/metrics_helpers.h
index 990a9fe..b0bbec2 100644
--- a/chrome/common/metrics_helpers.h
+++ b/chrome/common/metrics_helpers.h
@@ -13,7 +13,7 @@
 #include <string>
 
 #include "base/basictypes.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "chrome/common/page_transition_types.h"
 
@@ -54,8 +54,8 @@ class MetricsLogBase {
                        base::TimeDelta load_time);
 
   // Record any changes in a given histogram for transmission.
-  void RecordHistogramDelta(const Histogram& histogram,
-                            const Histogram::SampleSet& snapshot);
+  void RecordHistogramDelta(const base::Histogram& histogram,
+                            const base::Histogram::SampleSet& snapshot);
 
   // Stop writing to this record and generate the encoded representation.
   // None of the Record* methods can be called after this is called.
@@ -200,7 +200,7 @@ class MetricsServiceBase {
   void RecordCurrentHistograms();
 
   // Record a specific histogram .
-  void RecordHistogram(const Histogram& histogram);
+  void RecordHistogram(const base::Histogram& histogram);
 
   // A log that we are currently transmiting, or about to try to transmit.
   MetricsLogBase* pending_log_;
@@ -214,7 +214,7 @@ class MetricsServiceBase {
   MetricsLogBase* current_log_;
 
   // Maintain a map of histogram names to the sample stats we've sent.
-  typedef std::map<std::string, Histogram::SampleSet> LoggedSampleMap;
+  typedef std::map<std::string, base::Histogram::SampleSet> LoggedSampleMap;
 
   // For histograms, record what we've already logged (as a sample for each
   // histogram) so that we can send only the delta with the next log.
diff --git a/chrome/renderer/net/predictor_queue.cc b/chrome/renderer/net/predictor_queue.cc
index 40996e5..4f680ba 100644
--- a/chrome/renderer/net/predictor_queue.cc
+++ b/chrome/renderer/net/predictor_queue.cc
@@ -7,7 +7,7 @@
 #include "chrome/renderer/net/predictor_queue.h"
 
 #include "base/logging.h"
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
 
 DnsQueue::DnsQueue(BufferSize size)
     : buffer_(new char[size + 2]),
diff --git a/chrome/renderer/paint_aggregator.cc b/chrome/renderer/paint_aggregator.cc
index c5c4405..943e012 100644
--- a/chrome/renderer/paint_aggregator.cc
+++ b/chrome/renderer/paint_aggregator.cc
@@ -4,8 +4,8 @@
 
 #include "chrome/renderer/paint_aggregator.h"
 
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 
 // ----------------------------------------------------------------------------
 // ALGORITHM NOTES
@@ -25,7 +25,7 @@
 // If the combined area of paint rects contained within the scroll rect grows
 // too large, then we might as well just treat the scroll rect as a paint rect.
 // This constant sets the max ratio of paint rect area to scroll rect area that
-// we will tolerate before downgrading the scroll into a repaint.
+// we will tolerate before dograding the scroll into a repaint.
 static const float kMaxRedundantPaintToScrollArea = 0.8f;
 
 // The maximum number of paint rects.  If we exceed this limit, then we'll
@@ -227,7 +227,7 @@ void PaintAggregator::InvalidateScrollRect() {
 }
 
 void PaintAggregator::CombinePaintRects() {
-  // Combine paint rects down to at most two rects: one inside the scroll_rect
+  // Combine paint rects do to at most two rects: one inside the scroll_rect
   // and one outside the scroll_rect.  If there is no scroll_rect, then just
   // use the smallest bounding box for all paint rects.
   //
diff --git a/chrome/renderer/render_process_impl.cc b/chrome/renderer/render_process_impl.cc
index d23a08a..2350213 100644
--- a/chrome/renderer/render_process_impl.cc
+++ b/chrome/renderer/render_process_impl.cc
@@ -18,7 +18,7 @@
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
 #include "base/message_loop.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/sys_info.h"
 #include "base/utf_string_conversions.h"
@@ -159,7 +159,7 @@ RenderProcessImpl::RenderProcessImpl()
   }
 
   if (command_line.HasSwitch(switches::kDumpHistogramsOnExit)) {
-    StatisticsRecorder::set_dump_on_exit(true);
+    base::StatisticsRecorder::set_dump_on_exit(true);
   }
 
 #if !defined(DISABLE_NACL)
diff --git a/chrome/renderer/render_thread.cc b/chrome/renderer/render_thread.cc
index 595dc9c..f29bb0a 100644
--- a/chrome/renderer/render_thread.cc
+++ b/chrome/renderer/render_thread.cc
@@ -10,13 +10,13 @@
 #include <vector>
 
 #include "base/command_line.h"
-#include "base/field_trial.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/stats_table.h"
 #include "base/nullable_string16.h"
 #include "base/process_util.h"
 #include "base/shared_memory.h"
-#include "base/stats_table.h"
 #include "base/string_util.h"
 #include "base/task.h"
 #include "base/thread_local.h"
@@ -283,8 +283,8 @@ void RenderThread::Init() {
   // channel is established in time, EstablishGpuChannelSync will not block when
   // it is later called. Delays by a fixed period of time to avoid loading the
   // GPU immediately in an attempt to not slow startup time.
-  scoped_refptr<FieldTrial> prelaunch_trial(
-      new FieldTrial("PrelaunchGpuProcessExperiment", 100));
+  scoped_refptr<base::FieldTrial> prelaunch_trial(
+      new base::FieldTrial("PrelaunchGpuProcessExperiment", 100));
   int prelaunch_group = prelaunch_trial->AppendGroup("prelaunch_gpu_process",
                                                      kPrelauchGpuPercentage);
   if (prelaunch_group == prelaunch_trial->group() ||
@@ -808,8 +808,8 @@ static void* CreateHistogram(
     const char *name, int min, int max, size_t buckets) {
   if (min <= 0)
     min = 1;
-  scoped_refptr<Histogram> histogram = Histogram::FactoryGet(
-      name, min, max, buckets, Histogram::kUmaTargetedHistogramFlag);
+  scoped_refptr<base::Histogram> histogram = base::Histogram::FactoryGet(
+      name, min, max, buckets, base::Histogram::kUmaTargetedHistogramFlag);
   // We'll end up leaking these histograms, unless there is some code hiding in
   // there to do the dec-ref.
   // TODO(jar): Handle reference counting in webkit glue.
@@ -818,7 +818,7 @@ static void* CreateHistogram(
 }
 
 static void AddHistogramSample(void* hist, int sample) {
-  Histogram* histogram = static_cast<Histogram *>(hist);
+  base::Histogram* histogram = static_cast<base::Histogram*>(hist);
   histogram->Add(sample);
 }
 
@@ -834,7 +834,7 @@ void RenderThread::EnsureWebKitInitialized() {
         this, &RenderThread::IdleHandler);
   }
 
-  v8::V8::SetCounterFunction(StatsTable::FindLocation);
+  v8::V8::SetCounterFunction(base::StatsTable::FindLocation);
   v8::V8::SetCreateHistogramFunction(CreateHistogram);
   v8::V8::SetAddHistogramSampleFunction(AddHistogramSample);
 
diff --git a/chrome/renderer/render_view.cc b/chrome/renderer/render_view.cc
index 2ffaf26..0b17633 100644
--- a/chrome/renderer/render_view.cc
+++ b/chrome/renderer/render_view.cc
@@ -15,8 +15,8 @@
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
-#include "base/field_trial.h"
-#include "base/histogram.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/singleton.h"
@@ -5065,33 +5065,33 @@ void RenderView::DumpLoadHistograms() const {
   }
 
   // Histograms to determine if DNS prefetching has an impact on PLT.
-  static bool use_dns_histogram(FieldTrialList::Find("DnsImpact") &&
-      !FieldTrialList::Find("DnsImpact")->group_name().empty());
+  static bool use_dns_histogram(base::FieldTrialList::Find("DnsImpact") &&
+      !base::FieldTrialList::Find("DnsImpact")->group_name().empty());
   if (use_dns_histogram) {
     UMA_HISTOGRAM_ENUMERATION(
-        FieldTrial::MakeName("PLT.Abandoned", "DnsImpact"),
+        base::FieldTrial::MakeName("PLT.Abandoned", "DnsImpact"),
         abandoned_page ? 1 : 0, 2);
     UMA_HISTOGRAM_ENUMERATION(
-        FieldTrial::MakeName("PLT.LoadType", "DnsImpact"),
+        base::FieldTrial::MakeName("PLT.LoadType", "DnsImpact"),
         load_type, NavigationState::kLoadTypeMax);
     switch (load_type) {
       case NavigationState::NORMAL_LOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_NormalLoad", "DnsImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_NORMAL:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadNormal", "DnsImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_RELOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadReload", "DnsImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_CACHE_STALE_OK:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadStaleOk", "DnsImpact"),
             begin_to_finish_all_loads);
         break;
@@ -5102,66 +5102,68 @@ void RenderView::DumpLoadHistograms() const {
 
   // Histograms to determine if content prefetching has an impact on PLT.
   static const bool prefetching_fieldtrial =
-      FieldTrialList::Find("Prefetch") &&
-      !FieldTrialList::Find("Prefetch")->group_name().empty();
+      base::FieldTrialList::Find("Prefetch") &&
+      !base::FieldTrialList::Find("Prefetch")->group_name().empty();
   if (prefetching_fieldtrial) {
     if (navigation_state->was_prefetcher()) {
       PLT_HISTOGRAM(
-          FieldTrial::MakeName("PLT.BeginToFinishDoc_ContentPrefetcher",
+          base::FieldTrial::MakeName("PLT.BeginToFinishDoc_ContentPrefetcher",
                                "Prefetch"),
           begin_to_finish_doc);
       PLT_HISTOGRAM(
-          FieldTrial::MakeName("PLT.BeginToFinish_ContentPrefetcher",
-                               "Prefetch"),
+          base::FieldTrial::MakeName("PLT.BeginToFinish_ContentPrefetcher",
+                                     "Prefetch"),
           begin_to_finish_all_loads);
     }
     if (navigation_state->was_referred_by_prefetcher()) {
-      PLT_HISTOGRAM(
-          FieldTrial::MakeName("PLT.BeginToFinishDoc_ContentPrefetcherReferrer",
-                               "Prefetch"),
+      PLT_HISTOGRAM(base::FieldTrial::MakeName(
+              "PLT.BeginToFinishDoc_ContentPrefetcherReferrer",
+              "Prefetch"),
           begin_to_finish_doc);
-      PLT_HISTOGRAM(
-          FieldTrial::MakeName("PLT.BeginToFinish_ContentPrefetcherReferrer",
-                               "Prefetch"),
+      PLT_HISTOGRAM(base::FieldTrial::MakeName(
+              "PLT.BeginToFinish_ContentPrefetcherReferrer",
+              "Prefetch"),
           begin_to_finish_all_loads);
     }
-    UMA_HISTOGRAM_ENUMERATION(FieldTrial::MakeName("PLT.Abandoned", "Prefetch"),
-                              abandoned_page ? 1 : 0, 2);
-    PLT_HISTOGRAM(FieldTrial::MakeName("PLT.BeginToFinishDoc", "Prefetch"),
+    UMA_HISTOGRAM_ENUMERATION(
+        base::FieldTrial::MakeName("PLT.Abandoned", "Prefetch"),
+                                   abandoned_page ? 1 : 0, 2);
+    PLT_HISTOGRAM(base::FieldTrial::MakeName("PLT.BeginToFinishDoc",
+                                             "Prefetch"),
                   begin_to_finish_doc);
-    PLT_HISTOGRAM(FieldTrial::MakeName("PLT.BeginToFinish", "Prefetch"),
+    PLT_HISTOGRAM(base::FieldTrial::MakeName("PLT.BeginToFinish", "Prefetch"),
                   begin_to_finish_all_loads);
   }
 
   // Histograms to determine if backup connection jobs have an impact on PLT.
   static const bool connect_backup_jobs_fieldtrial(
-      FieldTrialList::Find("ConnnectBackupJobs") &&
-      !FieldTrialList::Find("ConnnectBackupJobs")->group_name().empty());
+      base::FieldTrialList::Find("ConnnectBackupJobs") &&
+      !base::FieldTrialList::Find("ConnnectBackupJobs")->group_name().empty());
   if (connect_backup_jobs_fieldtrial) {
     UMA_HISTOGRAM_ENUMERATION(
-        FieldTrial::MakeName("PLT.Abandoned", "ConnnectBackupJobs"),
+        base::FieldTrial::MakeName("PLT.Abandoned", "ConnnectBackupJobs"),
         abandoned_page ? 1 : 0, 2);
     UMA_HISTOGRAM_ENUMERATION(
-        FieldTrial::MakeName("PLT.LoadType", "ConnnectBackupJobs"),
+        base::FieldTrial::MakeName("PLT.LoadType", "ConnnectBackupJobs"),
         load_type, NavigationState::kLoadTypeMax);
     switch (load_type) {
       case NavigationState::NORMAL_LOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_NormalLoad", "ConnnectBackupJobs"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_NORMAL:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadNormal", "ConnnectBackupJobs"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_RELOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadReload", "ConnnectBackupJobs"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_CACHE_STALE_OK:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadStaleOk", "ConnnectBackupJobs"),
             begin_to_finish_all_loads);
         break;
@@ -5175,30 +5177,30 @@ void RenderView::DumpLoadHistograms() const {
   // TODO(jar): Consider removing the per-link-type versions.  We
   //   really only need LINK_LOAD_NORMAL and NORMAL_LOAD.
   static bool use_connection_impact_histogram(
-      FieldTrialList::Find("ConnCountImpact") &&
-      !FieldTrialList::Find("ConnCountImpact")->group_name().empty());
+      base::FieldTrialList::Find("ConnCountImpact") &&
+      !base::FieldTrialList::Find("ConnCountImpact")->group_name().empty());
   if (use_connection_impact_histogram) {
     UMA_HISTOGRAM_ENUMERATION(
-        FieldTrial::MakeName("PLT.Abandoned", "ConnCountImpact"),
+        base::FieldTrial::MakeName("PLT.Abandoned", "ConnCountImpact"),
         abandoned_page ? 1 : 0, 2);
     switch (load_type) {
       case NavigationState::NORMAL_LOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_NormalLoad", "ConnCountImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_NORMAL:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadNormal", "ConnCountImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_RELOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadReload", "ConnCountImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_CACHE_STALE_OK:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadStaleOk", "ConnCountImpact"),
             begin_to_finish_all_loads);
         break;
@@ -5209,30 +5211,30 @@ void RenderView::DumpLoadHistograms() const {
 
   // Histograms to determine effect of idle socket timeout.
   static bool use_idle_socket_timeout_histogram(
-      FieldTrialList::Find("IdleSktToImpact") &&
-      !FieldTrialList::Find("IdleSktToImpact")->group_name().empty());
+      base::FieldTrialList::Find("IdleSktToImpact") &&
+      !base::FieldTrialList::Find("IdleSktToImpact")->group_name().empty());
   if (use_idle_socket_timeout_histogram) {
     UMA_HISTOGRAM_ENUMERATION(
-        FieldTrial::MakeName("PLT.Abandoned", "IdleSktToImpact"),
+        base::FieldTrial::MakeName("PLT.Abandoned", "IdleSktToImpact"),
         abandoned_page ? 1 : 0, 2);
     switch (load_type) {
       case NavigationState::NORMAL_LOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_NormalLoad", "IdleSktToImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_NORMAL:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadNormal", "IdleSktToImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_RELOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadReload", "IdleSktToImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_CACHE_STALE_OK:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadStaleOk", "IdleSktToImpact"),
             begin_to_finish_all_loads);
         break;
@@ -5243,30 +5245,31 @@ void RenderView::DumpLoadHistograms() const {
 
   // Histograms to determine effect of number of connections per proxy.
   static bool use_proxy_connection_impact_histogram(
-      FieldTrialList::Find("ProxyConnectionImpact") &&
-      !FieldTrialList::Find("ProxyConnectionImpact")->group_name().empty());
+      base::FieldTrialList::Find("ProxyConnectionImpact") &&
+      !base::FieldTrialList::Find("ProxyConnectionImpact")->
+          group_name().empty());
   if (use_proxy_connection_impact_histogram) {
     UMA_HISTOGRAM_ENUMERATION(
-        FieldTrial::MakeName("PLT.Abandoned", "ProxyConnectionImpact"),
+        base::FieldTrial::MakeName("PLT.Abandoned", "ProxyConnectionImpact"),
         abandoned_page ? 1 : 0, 2);
     switch (load_type) {
       case NavigationState::NORMAL_LOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_NormalLoad", "ProxyConnectionImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_NORMAL:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadNormal", "ProxyConnectionImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_RELOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadReload", "ProxyConnectionImpact"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_CACHE_STALE_OK:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadStaleOk", "ProxyConnectionImpact"),
             begin_to_finish_all_loads);
         break;
@@ -5277,35 +5280,35 @@ void RenderView::DumpLoadHistograms() const {
 
   // Histograms to determine if SDCH has an impact.
   // TODO(jar): Consider removing per-link load types and the enumeration.
-  static bool use_sdch_histogram(FieldTrialList::Find("GlobalSdch") &&
-      !FieldTrialList::Find("GlobalSdch")->group_name().empty());
+  static bool use_sdch_histogram(base::FieldTrialList::Find("GlobalSdch") &&
+      !base::FieldTrialList::Find("GlobalSdch")->group_name().empty());
   if (use_sdch_histogram) {
     UMA_HISTOGRAM_ENUMERATION(
-        FieldTrial::MakeName("PLT.LoadType", "GlobalSdch"),
+        base::FieldTrial::MakeName("PLT.LoadType", "GlobalSdch"),
         load_type, NavigationState::kLoadTypeMax);
     switch (load_type) {
       case NavigationState::NORMAL_LOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_NormalLoad", "GlobalSdch"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_NORMAL:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadNormal", "GlobalSdch"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_RELOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadReload", "GlobalSdch"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_CACHE_STALE_OK:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadStaleOk", "GlobalSdch"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_CACHE_ONLY:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadCacheOnly", "GlobalSdch"),
             begin_to_finish_all_loads);
         break;
@@ -5315,56 +5318,57 @@ void RenderView::DumpLoadHistograms() const {
   }
 
   // Histograms to determine if cache size has an impact on PLT.
-  static bool use_cache_histogram1(FieldTrialList::Find("CacheSize") &&
-      !FieldTrialList::Find("CacheSize")->group_name().empty());
-  if (use_cache_histogram1 && NavigationState::LINK_LOAD_NORMAL <= load_type &&
+  static bool use_cache_histogram1(base::FieldTrialList::Find("CacheSize") &&
+      !base::FieldTrialList::Find("CacheSize")->group_name().empty());
+  if (use_cache_histogram1 &&
+      NavigationState::LINK_LOAD_NORMAL <= load_type &&
       NavigationState::LINK_LOAD_CACHE_ONLY >= load_type) {
     // TODO(mbelshe): Do we really want BeginToFinishDoc here?  It seems like
     //                StartToFinish or BeginToFinish would be better.
-    PLT_HISTOGRAM(FieldTrial::MakeName(
+    PLT_HISTOGRAM(base::FieldTrial::MakeName(
         "PLT.BeginToFinishDoc_LinkLoad", "CacheSize"), begin_to_finish_doc);
   }
 
   // Histograms to determine if cache throttling has an impact on PLT.
-  static bool use_cache_histogram2(FieldTrialList::Find("CacheThrottle") &&
-      !FieldTrialList::Find("CacheThrottle")->group_name().empty());
+  static bool use_cache_histogram2(base::FieldTrialList::Find("CacheThrottle") &&
+      !base::FieldTrialList::Find("CacheThrottle")->group_name().empty());
   if (use_cache_histogram2) {
     UMA_HISTOGRAM_ENUMERATION(
-        FieldTrial::MakeName("PLT.Abandoned", "CacheThrottle"),
+        base::FieldTrial::MakeName("PLT.Abandoned", "CacheThrottle"),
         abandoned_page ? 1 : 0, 2);
     switch (load_type) {
       case NavigationState::RELOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_Reload", "CacheThrottle"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::HISTORY_LOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_HistoryLoad", "CacheThrottle"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::NORMAL_LOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_NormalLoad", "CacheThrottle"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_NORMAL:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadNormal", "CacheThrottle"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_RELOAD:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadReload", "CacheThrottle"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_CACHE_STALE_OK:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadStaleOk", "CacheThrottle"),
             begin_to_finish_all_loads);
         break;
       case NavigationState::LINK_LOAD_CACHE_ONLY:
-        PLT_HISTOGRAM(FieldTrial::MakeName(
+        PLT_HISTOGRAM(base::FieldTrial::MakeName(
             "PLT.BeginToFinish_LinkLoadCacheOnly", "CacheThrottle"),
             begin_to_finish_all_loads);
         break;
@@ -5373,7 +5377,7 @@ void RenderView::DumpLoadHistograms() const {
     }
     if (NavigationState::RELOAD <= load_type &&
         NavigationState::LINK_LOAD_CACHE_ONLY >= load_type) {
-      PLT_HISTOGRAM(FieldTrial::MakeName(
+      PLT_HISTOGRAM(base::FieldTrial::MakeName(
           "PLT.BeginToFinish", "CacheThrottle"),
            begin_to_finish_all_loads);
     }
@@ -5385,14 +5389,16 @@ void RenderView::DumpLoadHistograms() const {
   //   if we asked for a HTTP request, we got a HTTP request
   // Due to spdy version mismatches, it is possible that we ask for SPDY
   // but didn't get SPDY.
-  static bool use_spdy_histogram(FieldTrialList::Find("SpdyImpact") &&
-      !FieldTrialList::Find("SpdyImpact")->group_name().empty());
+  static bool use_spdy_histogram(base::FieldTrialList::Find("SpdyImpact") &&
+      !base::FieldTrialList::Find("SpdyImpact")->group_name().empty());
   if (use_spdy_histogram) {
     // We take extra effort to only compute these once.
     static bool in_spdy_trial =
-        FieldTrialList::Find("SpdyImpact")->group_name() == "npn_with_spdy";
+        base::FieldTrialList::Find("SpdyImpact")->group_name() ==
+        "npn_with_spdy";
     static bool in_http_trial =
-        FieldTrialList::Find("SpdyImpact")->group_name() == "npn_with_http";
+        base::FieldTrialList::Find("SpdyImpact")->group_name() ==
+        "npn_with_http";
 
     bool spdy_trial_success = navigation_state->was_fetched_via_spdy() ?
         in_spdy_trial : in_http_trial;
@@ -5403,28 +5409,28 @@ void RenderView::DumpLoadHistograms() const {
       if (scheme_type == URLPattern::SCHEME_HTTPS &&
           navigation_state->was_npn_negotiated()) {
         UMA_HISTOGRAM_ENUMERATION(
-            FieldTrial::MakeName("PLT.Abandoned", "SpdyImpact"),
+            base::FieldTrial::MakeName("PLT.Abandoned", "SpdyImpact"),
             abandoned_page ? 1 : 0, 2);
         switch (load_type) {
           case NavigationState::LINK_LOAD_NORMAL:
-            PLT_HISTOGRAM(FieldTrial::MakeName(
+            PLT_HISTOGRAM(base::FieldTrial::MakeName(
                 "PLT.BeginToFinish_LinkLoadNormal_SpdyTrial", "SpdyImpact"),
                 begin_to_finish_all_loads);
-            PLT_HISTOGRAM(FieldTrial::MakeName(
+            PLT_HISTOGRAM(base::FieldTrial::MakeName(
                 "PLT.StartToFinish_LinkLoadNormal_SpdyTrial", "SpdyImpact"),
                 start_to_finish_all_loads);
-            PLT_HISTOGRAM(FieldTrial::MakeName(
+            PLT_HISTOGRAM(base::FieldTrial::MakeName(
                 "PLT.StartToCommit_LinkLoadNormal_SpdyTrial", "SpdyImpact"),
                 start_to_commit);
             break;
           case NavigationState::NORMAL_LOAD:
-            PLT_HISTOGRAM(FieldTrial::MakeName(
+            PLT_HISTOGRAM(base::FieldTrial::MakeName(
                 "PLT.BeginToFinish_NormalLoad_SpdyTrial", "SpdyImpact"),
                 begin_to_finish_all_loads);
-            PLT_HISTOGRAM(FieldTrial::MakeName(
+            PLT_HISTOGRAM(base::FieldTrial::MakeName(
                 "PLT.StartToFinish_NormalLoad_SpdyTrial", "SpdyImpact"),
                 start_to_finish_all_loads);
-            PLT_HISTOGRAM(FieldTrial::MakeName(
+            PLT_HISTOGRAM(base::FieldTrial::MakeName(
                 "PLT.StartToCommit_NormalLoad_SpdyTrial", "SpdyImpact"),
                 start_to_commit);
             break;
@@ -5439,7 +5445,7 @@ void RenderView::DumpLoadHistograms() const {
           navigation_state->was_alternate_protocol_available()) {
         if (!navigation_state->was_npn_negotiated()) {
           // This means that even there is alternate protocols for npn_http or
-          // npn_spdy, they are not taken (due to the fieldtrial).
+          // npn_spdy, they are not taken (due to the base::FieldTrial).
           switch (load_type) {
             case NavigationState::LINK_LOAD_NORMAL:
               PLT_HISTOGRAM(
diff --git a/chrome/renderer/render_widget.cc b/chrome/renderer/render_widget.cc
index f5a7ebe..8880a03 100644
--- a/chrome/renderer/render_widget.cc
+++ b/chrome/renderer/render_widget.cc
@@ -7,8 +7,8 @@
 #include "app/surface/transport_dib.h"
 #include "base/command_line.h"
 #include "base/logging.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/scoped_ptr.h"
 #include "build/build_config.h"
 #include "chrome/common/chrome_switches.h"
diff --git a/chrome/renderer/renderer_histogram_snapshots.cc b/chrome/renderer/renderer_histogram_snapshots.cc
index 5246141..ae9ee1d 100644
--- a/chrome/renderer/renderer_histogram_snapshots.cc
+++ b/chrome/renderer/renderer_histogram_snapshots.cc
@@ -6,15 +6,18 @@
 
 #include <ctype.h>
 
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/renderer/render_process.h"
 #include "chrome/renderer/render_thread.h"
 
 // TODO(raman): Before renderer shuts down send final snapshot lists.
 
+using base::Histogram;
+using base::StatisticsRecorder;
+
 RendererHistogramSnapshots::RendererHistogramSnapshots()
     : ALLOW_THIS_IN_INITIALIZER_LIST(
         renderer_histogram_snapshots_factory_(this)) {
diff --git a/chrome/renderer/renderer_histogram_snapshots.h b/chrome/renderer/renderer_histogram_snapshots.h
index d7e3f84..eff6f3e 100644
--- a/chrome/renderer/renderer_histogram_snapshots.h
+++ b/chrome/renderer/renderer_histogram_snapshots.h
@@ -11,7 +11,7 @@
 #include <vector>
 
 #include "base/basictypes.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/process.h"
 #include "base/task.h"
 
@@ -24,17 +24,17 @@ class RendererHistogramSnapshots {
   void SendHistograms(int sequence_number);
 
   // Maintain a map of histogram names to the sample stats we've sent.
-  typedef std::map<std::string, Histogram::SampleSet> LoggedSampleMap;
+  typedef std::map<std::string, base::Histogram::SampleSet> LoggedSampleMap;
   typedef std::vector<std::string> HistogramPickledList;
 
  private:
   // Extract snapshot data and then send it off the the Browser process.
   // Send only a delta to what we have already sent.
   void UploadAllHistrograms(int sequence_number);
-  void UploadHistrogram(const Histogram& histogram,
+  void UploadHistrogram(const base::Histogram& histogram,
                         HistogramPickledList* histograms);
-  void UploadHistogramDelta(const Histogram& histogram,
-                            const Histogram::SampleSet& snapshot,
+  void UploadHistogramDelta(const base::Histogram& histogram,
+                            const base::Histogram::SampleSet& snapshot,
                             HistogramPickledList* histograms);
 
   ScopedRunnableMethodFactory<RendererHistogramSnapshots>
diff --git a/chrome/renderer/renderer_main.cc b/chrome/renderer/renderer_main.cc
index dae703a..83dcd07 100644
--- a/chrome/renderer/renderer_main.cc
+++ b/chrome/renderer/renderer_main.cc
@@ -10,14 +10,14 @@
 #include "app/hi_res_timer_manager.h"
 #include "app/system_monitor.h"
 #include "base/command_line.h"
-#include "base/field_trial.h"
-#include "base/histogram.h"
+#include "base/metrics/field_trial.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/stats_counters.h"
 #include "base/path_service.h"
 #include "base/platform_thread.h"
 #include "base/process_util.h"
 #include "base/scoped_nsautorelease_pool.h"
-#include "base/stats_counters.h"
 #include "base/string_util.h"
 #include "base/trace_event.h"
 #include "chrome/common/chrome_constants.h"
@@ -223,7 +223,7 @@ int RendererMain(const MainFunctionParams& parameters) {
 
   RendererMainPlatformDelegate platform(parameters);
 
-  StatsScope<StatsCounterTimer>
+  base::StatsScope<base::StatsCounterTimer>
       startup_timer(chrome::Counters::renderer_main());
 
 #if defined(OS_MACOSX)
@@ -249,13 +249,13 @@ int RendererMain(const MainFunctionParams& parameters) {
 
   // Initialize histogram statistics gathering system.
   // Don't create StatisticsRecorder in the single process mode.
-  scoped_ptr<StatisticsRecorder> statistics;
-  if (!StatisticsRecorder::WasStarted()) {
-    statistics.reset(new StatisticsRecorder());
+  scoped_ptr<base::StatisticsRecorder> statistics;
+  if (!base::StatisticsRecorder::WasStarted()) {
+    statistics.reset(new base::StatisticsRecorder());
   }
 
   // Initialize statistical testing infrastructure.
-  FieldTrialList field_trial;
+  base::FieldTrialList field_trial;
   // Ensure any field trials in browser are reflected into renderer.
   if (parsed_command_line.HasSwitch(switches::kForceFieldTestNameAndValue)) {
     std::string persistent = parsed_command_line.GetSwitchValueASCII(
diff --git a/chrome/renderer/safe_browsing/features.cc b/chrome/renderer/safe_browsing/features.cc
index 40fd97b..29675db 100644
--- a/chrome/renderer/safe_browsing/features.cc
+++ b/chrome/renderer/safe_browsing/features.cc
@@ -4,8 +4,8 @@
 
 #include "chrome/renderer/safe_browsing/features.h"
 
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 
 namespace safe_browsing {
 
diff --git a/chrome/renderer/safe_browsing/phishing_dom_feature_extractor.cc b/chrome/renderer/safe_browsing/phishing_dom_feature_extractor.cc
index e1db151..1f3e394 100644
--- a/chrome/renderer/safe_browsing/phishing_dom_feature_extractor.cc
+++ b/chrome/renderer/safe_browsing/phishing_dom_feature_extractor.cc
@@ -6,9 +6,9 @@
 
 #include "base/compiler_specific.h"
 #include "base/hash_tables.h"
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "chrome/renderer/render_view.h"
 #include "chrome/renderer/safe_browsing/feature_extractor_clock.h"
diff --git a/chrome/renderer/safe_browsing/phishing_term_feature_extractor.cc b/chrome/renderer/safe_browsing/phishing_term_feature_extractor.cc
index 0ec0dbc..ea5af10 100644
--- a/chrome/renderer/safe_browsing/phishing_term_feature_extractor.cc
+++ b/chrome/renderer/safe_browsing/phishing_term_feature_extractor.cc
@@ -9,10 +9,10 @@
 
 #include "app/l10n_util.h"
 #include "base/compiler_specific.h"
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/sha2.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/renderer/safe_browsing/feature_extractor_clock.h"
diff --git a/chrome/renderer/safe_browsing/phishing_url_feature_extractor.cc b/chrome/renderer/safe_browsing/phishing_url_feature_extractor.cc
index 54f924a..9298749 100644
--- a/chrome/renderer/safe_browsing/phishing_url_feature_extractor.cc
+++ b/chrome/renderer/safe_browsing/phishing_url_feature_extractor.cc
@@ -8,9 +8,9 @@
 #include <string>
 #include <vector>
 
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/perftimer.h"
+#include "base/metrics/histogram.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
 #include "chrome/renderer/safe_browsing/features.h"
diff --git a/chrome/renderer/spellchecker/spellcheck.cc b/chrome/renderer/spellchecker/spellcheck.cc
index ab4809e..4220f4a 100644
--- a/chrome/renderer/spellchecker/spellcheck.cc
+++ b/chrome/renderer/spellchecker/spellcheck.cc
@@ -5,7 +5,7 @@
 #include "chrome/renderer/spellchecker/spellcheck.h"
 
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/render_messages.h"
diff --git a/chrome/renderer/user_script_slave.cc b/chrome/renderer/user_script_slave.cc
index 032406f..c295294 100644
--- a/chrome/renderer/user_script_slave.cc
+++ b/chrome/renderer/user_script_slave.cc
@@ -6,11 +6,11 @@
 
 #include "app/resource_bundle.h"
 #include "base/command_line.h"
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/perftimer.h"
 #include "base/pickle.h"
 #include "base/shared_memory.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension.h"
diff --git a/chrome/renderer/webplugin_delegate_pepper.cc b/chrome/renderer/webplugin_delegate_pepper.cc
index 292ef48..ea434f6 100644
--- a/chrome/renderer/webplugin_delegate_pepper.cc
+++ b/chrome/renderer/webplugin_delegate_pepper.cc
@@ -15,19 +15,19 @@
 
 #include "base/file_path.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
 #if defined(OS_MACOSX)
 #include "base/mac_util.h"
 #endif
 #include "base/md5.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/stats_counters.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #if defined(OS_MACOSX)
 #include "base/scoped_cftyperef.h"
 #endif
 #include "base/scoped_ptr.h"
-#include "base/stats_counters.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/task.h"
diff --git a/chrome/test/unit/chrome_test_suite.cc b/chrome/test/unit/chrome_test_suite.cc
index d9b9c65..9613341 100644
--- a/chrome/test/unit/chrome_test_suite.cc
+++ b/chrome/test/unit/chrome_test_suite.cc
@@ -7,9 +7,9 @@
 #include "app/app_paths.h"
 #include "app/resource_bundle.h"
 #include "base/command_line.h"
+#include "base/metrics/stats_table.h"
 #include "base/process_util.h"
 #include "base/scoped_nsautorelease_pool.h"
-#include "base/stats_table.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/common/chrome_constants.h"
@@ -120,8 +120,8 @@ void ChromeTestSuite::Initialize() {
   std::string pid_string = StringPrintf("-%d", base::GetCurrentProcId());
   stats_filename_ += pid_string;
   RemoveSharedMemoryFile(stats_filename_);
-  stats_table_ = new StatsTable(stats_filename_, 20, 200);
-  StatsTable::set_current(stats_table_);
+  stats_table_ = new base::StatsTable(stats_filename_, 20, 200);
+  base::StatsTable::set_current(stats_table_);
 }
 
 void ChromeTestSuite::Shutdown() {
@@ -135,7 +135,7 @@ void ChromeTestSuite::Shutdown() {
   g_browser_process = NULL;
 
   // Tear down shared StatsTable; prevents unit_tests from leaking it.
-  StatsTable::set_current(NULL);
+  base::StatsTable::set_current(NULL);
   delete stats_table_;
   RemoveSharedMemoryFile(stats_filename_);
 
diff --git a/chrome/test/unit/chrome_test_suite.h b/chrome/test/unit/chrome_test_suite.h
index 7f63c4e..87a644d 100644
--- a/chrome/test/unit/chrome_test_suite.h
+++ b/chrome/test/unit/chrome_test_suite.h
@@ -19,7 +19,9 @@
 #include "net/base/mock_host_resolver.h"
 #include "net/base/net_util.h"
 
+namespace base {
 class StatsTable;
+}
 
 // In many cases it may be not obvious that a test makes a real DNS lookup.
 // We generally don't want to rely on external DNS servers for our tests,
@@ -50,7 +52,8 @@ class ChromeTestSuite : public base::TestSuite {
     browser_dir_ = browser_dir;
   }
 
-  StatsTable* stats_table_;
+  base::StatsTable* stats_table_;
+
   // The name used for the stats file so it can be cleaned up on posix during
   // test shutdown.
   std::string stats_filename_;
diff --git a/chrome_frame/chrome_frame_activex_base.h b/chrome_frame/chrome_frame_activex_base.h
index 84fccd5..e5b1097 100644
--- a/chrome_frame/chrome_frame_activex_base.h
+++ b/chrome_frame/chrome_frame_activex_base.h
@@ -16,7 +16,7 @@
 #include <string>
 #include <vector>
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/scoped_bstr_win.h"
 #include "base/scoped_comptr_win.h"
 #include "base/scoped_variant_win.h"
diff --git a/chrome_frame/chrome_frame_histograms.cc b/chrome_frame/chrome_frame_histograms.cc
index 3dac19f..a920828 100644
--- a/chrome_frame/chrome_frame_histograms.cc
+++ b/chrome_frame/chrome_frame_histograms.cc
@@ -4,11 +4,14 @@
 
 #include "chrome_frame/chrome_frame_histograms.h"
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 
+using base::Histogram;
+using base::StatisticsRecorder;
+
   // Initialize histogram statistics gathering system.
 base::LazyInstance<StatisticsRecorder>
     g_statistics_recorder_(base::LINKER_INITIALIZED);
diff --git a/chrome_frame/chrome_frame_histograms.h b/chrome_frame/chrome_frame_histograms.h
index 0afcc69..b33efac 100644
--- a/chrome_frame/chrome_frame_histograms.h
+++ b/chrome_frame/chrome_frame_histograms.h
@@ -11,7 +11,7 @@
 
 #include "base/basictypes.h"
 #include "base/lock.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/process.h"
 #include "base/scoped_ptr.h"
 #include "base/task.h"
@@ -26,7 +26,7 @@
 class ChromeFrameHistogramSnapshots {
  public:
   // Maintain a map of histogram names to the sample stats we've sent.
-  typedef std::map<std::string, Histogram::SampleSet> LoggedSampleMap;
+  typedef std::map<std::string, base::Histogram::SampleSet> LoggedSampleMap;
   typedef std::vector<std::string> HistogramPickledList;
 
   ChromeFrameHistogramSnapshots();
@@ -38,11 +38,11 @@ class ChromeFrameHistogramSnapshots {
   HistogramPickledList GatherAllHistograms();
 
  private:
-  void GatherHistogram(const Histogram& histogram,
+  void GatherHistogram(const base::Histogram& histogram,
                        HistogramPickledList* histograms);
 
-  void GatherHistogramDelta(const Histogram& histogram,
-                            const Histogram::SampleSet& snapshot,
+  void GatherHistogramDelta(const base::Histogram& histogram,
+                            const base::Histogram::SampleSet& snapshot,
                             HistogramPickledList* histograms);
 
   // For histograms, record what we've already logged (as a sample for each
diff --git a/chrome_frame/crash_reporting/crash_metrics.cc b/chrome_frame/crash_reporting/crash_metrics.cc
index 81c2296..3a6c9ee 100644
--- a/chrome_frame/crash_reporting/crash_metrics.cc
+++ b/chrome_frame/crash_reporting/crash_metrics.cc
@@ -4,7 +4,7 @@
 
 #include "chrome_frame/crash_reporting/crash_metrics.h"
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/registry.h"
 #include "chrome_frame/utils.h"
 
diff --git a/chrome_frame/metrics_service.cc b/chrome_frame/metrics_service.cc
index 20d55ce..4e46708 100644
--- a/chrome_frame/metrics_service.cc
+++ b/chrome_frame/metrics_service.cc
@@ -125,7 +125,7 @@ base::LazyInstance<base::Thread, UploadThreadInstanceTraits>
 
 Lock g_metrics_service_lock;
 
-extern base::LazyInstance<StatisticsRecorder> g_statistics_recorder_;
+extern base::LazyInstance<base::StatisticsRecorder> g_statistics_recorder_;
 
 // This class provides HTTP request context information for metrics upload
 // requests initiated by ChromeFrame.
diff --git a/chrome_frame/metrics_service.h b/chrome_frame/metrics_service.h
index 252f716..38eb1f4 100644
--- a/chrome_frame/metrics_service.h
+++ b/chrome_frame/metrics_service.h
@@ -12,8 +12,8 @@
 #include <string>
 
 #include "base/basictypes.h"
-#include "base/histogram.h"
 #include "base/lazy_instance.h"
+#include "base/metrics/histogram.h"
 #include "base/platform_thread.h"
 #include "base/scoped_ptr.h"
 #include "base/thread_local.h"
@@ -49,7 +49,7 @@ class MetricsService : public MetricsServiceBase {
   };
 
   // Maintain a map of histogram names to the sample stats we've sent.
-  typedef std::map<std::string, Histogram::SampleSet> LoggedSampleMap;
+  typedef std::map<std::string, base::Histogram::SampleSet> LoggedSampleMap;
 
   // Sets and gets whether metrics recording is active.
   // SetRecording(false) also forces a persistent save of logging state (if
diff --git a/chrome_frame/utils.h b/chrome_frame/utils.h
index 8189faf..4ec548a 100644
--- a/chrome_frame/utils.h
+++ b/chrome_frame/utils.h
@@ -13,9 +13,9 @@
 #include <string>
 
 #include "base/basictypes.h"
-#include "base/histogram.h"
 #include "base/lock.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/thread.h"
 #include "gfx/rect.h"
 #include "googleurl/src/gurl.h"
@@ -433,8 +433,8 @@ extern Lock g_ChromeFrameHistogramLock;
 
 // Thread safe versions of the UMA histogram macros we use for ChromeFrame.
 // These should be used for histograms in ChromeFrame. If other histogram
-// macros from base/histogram.h are needed then thread safe versions of those
-// should be defined and used.
+// macros from base/metrics/histogram.h are needed then thread safe versions of
+// those should be defined and used.
 #define THREAD_SAFE_UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, \
                                                 bucket_count) { \
   AutoLock lock(g_ChromeFrameHistogramLock); \
diff --git a/ipc/ipc_channel_posix.cc b/ipc/ipc_channel_posix.cc
index 1c1b4e6..3dded13 100644
--- a/ipc/ipc_channel_posix.cc
+++ b/ipc/ipc_channel_posix.cc
@@ -23,7 +23,6 @@
 #include "base/process_util.h"
 #include "base/scoped_ptr.h"
 #include "base/singleton.h"
-#include "base/stats_counters.h"
 #include "base/string_util.h"
 #include "ipc/ipc_descriptors.h"
 #include "ipc/ipc_switches.h"
diff --git a/ipc/ipc_channel_win.cc b/ipc/ipc_channel_win.cc
index 051bb8d..e6bcd3c 100644
--- a/ipc/ipc_channel_win.cc
+++ b/ipc/ipc_channel_win.cc
@@ -11,7 +11,6 @@
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/non_thread_safe.h"
-#include "base/stats_counters.h"
 #include "base/utf_string_conversions.h"
 #include "base/win_util.h"
 #include "ipc/ipc_logging.h"
diff --git a/media/audio/linux/alsa_output.cc b/media/audio/linux/alsa_output.cc
index 9a07493..09d9f79 100644
--- a/media/audio/linux/alsa_output.cc
+++ b/media/audio/linux/alsa_output.cc
@@ -659,7 +659,7 @@ void AlsaPcmOutputStream::ScheduleNextWrite(bool source_exhausted) {
           NewRunnableMethod(this, &AlsaPcmOutputStream::WriteTask));
     } else {
       // TODO(ajwong): Measure the reliability of the delay interval.  Use
-      // base/histogram.h.
+      // base/metrics/histogram.h.
       message_loop_->PostDelayedTask(
           FROM_HERE,
           NewRunnableMethod(this, &AlsaPcmOutputStream::WriteTask),
diff --git a/net/base/bandwidth_metrics.h b/net/base/bandwidth_metrics.h
index c82d1a9..80fa005 100644
--- a/net/base/bandwidth_metrics.h
+++ b/net/base/bandwidth_metrics.h
@@ -8,7 +8,7 @@
 
 #include <list>
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/logging.h"
 #include "base/time.h"
 
diff --git a/net/base/connection_type_histograms.cc b/net/base/connection_type_histograms.cc
index de780f2..5146e91e 100644
--- a/net/base/connection_type_histograms.cc
+++ b/net/base/connection_type_histograms.cc
@@ -4,7 +4,7 @@
 
 #include "net/base/connection_type_histograms.h"
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 
 namespace net {
 
diff --git a/net/base/cookie_monster.cc b/net/base/cookie_monster.cc
index fae7671..455a739 100644
--- a/net/base/cookie_monster.cc
+++ b/net/base/cookie_monster.cc
@@ -48,8 +48,8 @@
 
 #include "base/basictypes.h"
 #include "base/format_macros.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/scoped_ptr.h"
 #include "base/string_tokenizer.h"
 #include "base/string_util.h"
@@ -148,49 +148,49 @@ CookieMonster::~CookieMonster() {
 // initialization is based are included in comments below.
 void CookieMonster::InitializeHistograms() {
   // From UMA_HISTOGRAM_CUSTOM_COUNTS
-  histogram_expiration_duration_minutes_ = Histogram::FactoryGet(
+  histogram_expiration_duration_minutes_ = base::Histogram::FactoryGet(
       "Cookie.ExpirationDurationMinutes",
       1, kMinutesInTenYears, 50,
-      Histogram::kUmaTargetedHistogramFlag);
-  histogram_between_access_interval_minutes_ = Histogram::FactoryGet(
+      base::Histogram::kUmaTargetedHistogramFlag);
+  histogram_between_access_interval_minutes_ = base::Histogram::FactoryGet(
       "Cookie.BetweenAccessIntervalMinutes",
       1, kMinutesInTenYears, 50,
-      Histogram::kUmaTargetedHistogramFlag);
-  histogram_evicted_last_access_minutes_ = Histogram::FactoryGet(
+      base::Histogram::kUmaTargetedHistogramFlag);
+  histogram_evicted_last_access_minutes_ = base::Histogram::FactoryGet(
       "Cookie.EvictedLastAccessMinutes",
       1, kMinutesInTenYears, 50,
-      Histogram::kUmaTargetedHistogramFlag);
-  histogram_count_ = Histogram::FactoryGet(
+      base::Histogram::kUmaTargetedHistogramFlag);
+  histogram_count_ = base::Histogram::FactoryGet(
       "Cookie.Count", 1, 4000, 50,
-      Histogram::kUmaTargetedHistogramFlag);
-  histogram_domain_count_ = Histogram::FactoryGet(
+      base::Histogram::kUmaTargetedHistogramFlag);
+  histogram_domain_count_ = base::Histogram::FactoryGet(
       "Cookie.DomainCount", 1, 4000, 50,
-      Histogram::kUmaTargetedHistogramFlag);
-  histogram_etldp1_count_ = Histogram::FactoryGet(
+      base::Histogram::kUmaTargetedHistogramFlag);
+  histogram_etldp1_count_ = base::Histogram::FactoryGet(
       "Cookie.Etldp1Count", 1, 4000, 50,
-      Histogram::kUmaTargetedHistogramFlag);
-  histogram_domain_per_etldp1_count_ = Histogram::FactoryGet(
+      base::Histogram::kUmaTargetedHistogramFlag);
+  histogram_domain_per_etldp1_count_ = base::Histogram::FactoryGet(
       "Cookie.DomainPerEtldp1Count", 1, 4000, 50,
-      Histogram::kUmaTargetedHistogramFlag);
+      base::Histogram::kUmaTargetedHistogramFlag);
 
   // From UMA_HISTOGRAM_COUNTS_10000 & UMA_HISTOGRAM_CUSTOM_COUNTS
-  histogram_number_duplicate_db_cookies_ = Histogram::FactoryGet(
+  histogram_number_duplicate_db_cookies_ = base::Histogram::FactoryGet(
       "Net.NumDuplicateCookiesInDb", 1, 10000, 50,
-      Histogram::kUmaTargetedHistogramFlag);
+      base::Histogram::kUmaTargetedHistogramFlag);
 
   // From UMA_HISTOGRAM_ENUMERATION
-  histogram_cookie_deletion_cause_ = LinearHistogram::FactoryGet(
+  histogram_cookie_deletion_cause_ = base::LinearHistogram::FactoryGet(
       "Cookie.DeletionCause", 1,
       DELETE_COOKIE_LAST_ENTRY - 1, DELETE_COOKIE_LAST_ENTRY,
-      Histogram::kUmaTargetedHistogramFlag);
+      base::Histogram::kUmaTargetedHistogramFlag);
 
   // From UMA_HISTOGRAM_{CUSTOM_,}TIMES
-  histogram_time_get_ = Histogram::FactoryTimeGet("Cookie.TimeGet",
+  histogram_time_get_ = base::Histogram::FactoryTimeGet("Cookie.TimeGet",
       base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(1),
-      50, Histogram::kUmaTargetedHistogramFlag);
-  histogram_time_load_ = Histogram::FactoryTimeGet("Cookie.TimeLoad",
+      50, base::Histogram::kUmaTargetedHistogramFlag);
+  histogram_time_load_ = base::Histogram::FactoryTimeGet("Cookie.TimeLoad",
       base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(1),
-      50, Histogram::kUmaTargetedHistogramFlag);
+      50, base::Histogram::kUmaTargetedHistogramFlag);
 }
 
 void CookieMonster::InitStore() {
diff --git a/net/base/cookie_monster.h b/net/base/cookie_monster.h
index 33953d9..2f18283 100644
--- a/net/base/cookie_monster.h
+++ b/net/base/cookie_monster.h
@@ -22,7 +22,10 @@
 #include "net/base/cookie_store.h"
 
 class GURL;
+
+namespace base {
 class Histogram;
+}
 
 namespace net {
 
@@ -409,17 +412,17 @@ class CookieMonster : public CookieStore {
 
   // Histogram variables; see CookieMonster::InitializeHistograms() in
   // cookie_monster.cc for details.
-  scoped_refptr<Histogram> histogram_expiration_duration_minutes_;
-  scoped_refptr<Histogram> histogram_between_access_interval_minutes_;
-  scoped_refptr<Histogram> histogram_evicted_last_access_minutes_;
-  scoped_refptr<Histogram> histogram_count_;
-  scoped_refptr<Histogram> histogram_domain_count_;
-  scoped_refptr<Histogram> histogram_etldp1_count_;
-  scoped_refptr<Histogram> histogram_domain_per_etldp1_count_;
-  scoped_refptr<Histogram> histogram_number_duplicate_db_cookies_;
-  scoped_refptr<Histogram> histogram_cookie_deletion_cause_;
-  scoped_refptr<Histogram> histogram_time_get_;
-  scoped_refptr<Histogram> histogram_time_load_;
+  scoped_refptr<base::Histogram> histogram_expiration_duration_minutes_;
+  scoped_refptr<base::Histogram> histogram_between_access_interval_minutes_;
+  scoped_refptr<base::Histogram> histogram_evicted_last_access_minutes_;
+  scoped_refptr<base::Histogram> histogram_count_;
+  scoped_refptr<base::Histogram> histogram_domain_count_;
+  scoped_refptr<base::Histogram> histogram_etldp1_count_;
+  scoped_refptr<base::Histogram> histogram_domain_per_etldp1_count_;
+  scoped_refptr<base::Histogram> histogram_number_duplicate_db_cookies_;
+  scoped_refptr<base::Histogram> histogram_cookie_deletion_cause_;
+  scoped_refptr<base::Histogram> histogram_time_get_;
+  scoped_refptr<base::Histogram> histogram_time_load_;
 
   // Initialize the above variables; should only be called from
   // the constructor.
diff --git a/net/base/file_stream_posix.cc b/net/base/file_stream_posix.cc
index 45c4cfb..1e20efe 100644
--- a/net/base/file_stream_posix.cc
+++ b/net/base/file_stream_posix.cc
@@ -17,9 +17,9 @@
 #include "base/callback.h"
 #include "base/eintr_wrapper.h"
 #include "base/file_path.h"
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/waitable_event.h"
 #include "base/worker_pool.h"
diff --git a/net/base/file_stream_win.cc b/net/base/file_stream_win.cc
index 234ddf9..9408ae0 100644
--- a/net/base/file_stream_win.cc
+++ b/net/base/file_stream_win.cc
@@ -7,9 +7,9 @@
 #include <windows.h>
 
 #include "base/file_path.h"
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "net/base/net_errors.h"
 
 namespace net {
diff --git a/net/base/host_resolver_impl.cc b/net/base/host_resolver_impl.cc
index 6d1e2ba..e3e3a94 100644
--- a/net/base/host_resolver_impl.cc
+++ b/net/base/host_resolver_impl.cc
@@ -17,9 +17,9 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/debug_util.h"
-#include "base/histogram.h"
 #include "base/lock.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
 #include "base/time.h"
diff --git a/net/base/mime_sniffer.cc b/net/base/mime_sniffer.cc
index 4ad4e1d..1a52b99 100644
--- a/net/base/mime_sniffer.cc
+++ b/net/base/mime_sniffer.cc
@@ -97,8 +97,8 @@
 #include "net/base/mime_sniffer.h"
 
 #include "base/basictypes.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/mime_util.h"
@@ -207,11 +207,11 @@ static const MagicNumber kSniffableTags[] = {
   MAGIC_HTML_TAG("p")  // Mozilla
 };
 
-static scoped_refptr<Histogram> UMASnifferHistogramGet(const char* name,
-                                                       int array_size) {
-  scoped_refptr<Histogram> counter =
-      LinearHistogram::FactoryGet(name, 1, array_size - 1, array_size,
-      Histogram::kUmaTargetedHistogramFlag);
+static scoped_refptr<base::Histogram> UMASnifferHistogramGet(const char* name,
+                                                             int array_size) {
+  scoped_refptr<base::Histogram> counter =
+      base::LinearHistogram::FactoryGet(name, 1, array_size - 1, array_size,
+      base::Histogram::kUmaTargetedHistogramFlag);
   return counter;
 }
 
@@ -251,7 +251,7 @@ static bool MatchMagicNumber(const char* content, size_t size,
 
 static bool CheckForMagicNumbers(const char* content, size_t size,
                                  const MagicNumber* magic, size_t magic_len,
-                                 Histogram* counter, std::string* result) {
+                                 base::Histogram* counter, std::string* result) {
   for (size_t i = 0; i < magic_len; ++i) {
     if (MatchMagicNumber(content, size, &(magic[i]), result)) {
       if (counter) counter->Add(static_cast<int>(i));
@@ -292,7 +292,7 @@ static bool SniffForHTML(const char* content,
     if (!IsAsciiWhitespace(*pos))
       break;
   }
-  static scoped_refptr<Histogram> counter =
+  static scoped_refptr<base::Histogram> counter =
       UMASnifferHistogramGet("mime_sniffer.kSniffableTags2",
                              arraysize(kSniffableTags));
   // |pos| now points to first non-whitespace character (or at end).
@@ -310,7 +310,7 @@ static bool SniffForMagicNumbers(const char* content,
   *have_enough_content &= TruncateSize(kBytesRequiredForMagic, &size);
 
   // Check our big table of Magic Numbers
-  static scoped_refptr<Histogram> counter =
+  static scoped_refptr<base::Histogram> counter =
       UMASnifferHistogramGet("mime_sniffer.kMagicNumbers2",
                              arraysize(kMagicNumbers));
   return CheckForMagicNumbers(content, size,
@@ -351,7 +351,7 @@ static bool SniffXML(const char* content,
   // We want to skip XML processing instructions (of the form "<?xml ...")
   // and stop at the first "plain" tag, then make a decision on the mime-type
   // based on the name (or possibly attributes) of that tag.
-  static scoped_refptr<Histogram> counter =
+  static scoped_refptr<base::Histogram> counter =
       UMASnifferHistogramGet("mime_sniffer.kMagicXML2",
                              arraysize(kMagicXML));
   const int kMaxTagIterations = 5;
@@ -435,7 +435,7 @@ static bool SniffBinary(const char* content,
   const bool is_truncated = TruncateSize(kMaxBytesToSniff, &size);
 
   // First, we look for a BOM.
-  static scoped_refptr<Histogram> counter =
+  static scoped_refptr<base::Histogram> counter =
       UMASnifferHistogramGet("mime_sniffer.kByteOrderMark2",
                              arraysize(kByteOrderMark));
   std::string unused;
@@ -477,7 +477,7 @@ static bool IsUnknownMimeType(const std::string& mime_type) {
     // Firefox rejects a mime type if it is exactly */*
     "*/*",
   };
-  static scoped_refptr<Histogram> counter =
+  static scoped_refptr<base::Histogram> counter =
       UMASnifferHistogramGet("mime_sniffer.kUnknownMimeTypes2",
                              arraysize(kUnknownMimeTypes) + 1);
   for (size_t i = 0; i < arraysize(kUnknownMimeTypes); ++i) {
@@ -503,7 +503,7 @@ static bool SniffCRX(const char* content,
                      const std::string& type_hint,
                      bool* have_enough_content,
                      std::string* result) {
-  static scoped_refptr<Histogram> counter =
+  static scoped_refptr<base::Histogram> counter =
       UMASnifferHistogramGet("mime_sniffer.kSniffCRX", 3);
 
   // Technically, the crx magic number is just Cr24, but the bytes after that
@@ -541,7 +541,7 @@ static bool SniffCRX(const char* content,
 }
 
 bool ShouldSniffMimeType(const GURL& url, const std::string& mime_type) {
-  static scoped_refptr<Histogram> should_sniff_counter =
+  static scoped_refptr<base::Histogram> should_sniff_counter =
       UMASnifferHistogramGet("mime_sniffer.ShouldSniffMimeType2", 3);
   // We are willing to sniff the mime type for HTTP, HTTPS, and FTP
   bool sniffable_scheme = url.is_empty() ||
@@ -566,7 +566,7 @@ bool ShouldSniffMimeType(const GURL& url, const std::string& mime_type) {
     "text/xml",
     "application/xml",
   };
-  static scoped_refptr<Histogram> counter =
+  static scoped_refptr<base::Histogram> counter =
       UMASnifferHistogramGet("mime_sniffer.kSniffableTypes2",
                              arraysize(kSniffableTypes) + 1);
   for (size_t i = 0; i < arraysize(kSniffableTypes); ++i) {
diff --git a/net/base/net_util.cc b/net/base/net_util.cc
index 9afae4c..27621e6 100644
--- a/net/base/net_util.cc
+++ b/net/base/net_util.cc
@@ -34,7 +34,6 @@
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/i18n/file_util_icu.h"
 #include "base/i18n/icu_string_conversions.h"
 #include "base/i18n/time_formatting.h"
@@ -42,6 +41,7 @@
 #include "base/lock.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/singleton.h"
 #include "base/stl_util-inl.h"
diff --git a/net/base/run_all_unittests.cc b/net/base/run_all_unittests.cc
index 5f2207d..685d8df 100644
--- a/net/base/run_all_unittests.cc
+++ b/net/base/run_all_unittests.cc
@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 #include "build/build_config.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/nss_util.h"
 #include "net/base/net_test_suite.h"
 #include "net/http/http_stream_factory.h"
@@ -13,7 +13,7 @@
 
 int main(int argc, char** argv) {
   // Record histograms, so we can get histograms data in tests.
-  StatisticsRecorder recorder;
+  base::StatisticsRecorder recorder;
   NetTestSuite test_suite(argc, argv);
 
 #if defined(OS_WIN)
diff --git a/net/base/sdch_filter.cc b/net/base/sdch_filter.cc
index a2b13d4..cc9a1d6 100644
--- a/net/base/sdch_filter.cc
+++ b/net/base/sdch_filter.cc
@@ -7,8 +7,8 @@
 #include <algorithm>
 
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "net/base/sdch_filter.h"
 #include "net/base/sdch_manager.h"
 
diff --git a/net/base/sdch_manager.cc b/net/base/sdch_manager.cc
index 21cbe07..15850d6 100644
--- a/net/base/sdch_manager.cc
+++ b/net/base/sdch_manager.cc
@@ -5,9 +5,8 @@
 #include "net/base/sdch_manager.h"
 
 #include "base/base64.h"
-#include "base/field_trial.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/sha2.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
diff --git a/net/base/x509_certificate.cc b/net/base/x509_certificate.cc
index 6395b97..e21a3bc 100644
--- a/net/base/x509_certificate.cc
+++ b/net/base/x509_certificate.cc
@@ -6,8 +6,8 @@
 
 #include <map>
 
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/singleton.h"
 #include "base/string_piece.h"
 #include "base/time.h"
diff --git a/net/disk_cache/backend_impl.cc b/net/disk_cache/backend_impl.cc
index 5086e2b..2ad91e0 100644
--- a/net/disk_cache/backend_impl.cc
+++ b/net/disk_cache/backend_impl.cc
@@ -4,11 +4,11 @@
 
 #include "net/disk_cache/backend_impl.h"
 
-#include "base/field_trial.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
 #include "base/rand_util.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
@@ -192,11 +192,12 @@ bool SetFieldTrialInfo(int size_group) {
 
   // Field trials involve static objects so we have to do this only once.
   first = false;
-  scoped_refptr<FieldTrial> trial1 = new FieldTrial("CacheSize", 10);
+  scoped_refptr<base::FieldTrial> trial1 =
+      new base::FieldTrial("CacheSize", 10);
   std::string group1 = base::StringPrintf("CacheSizeGroup_%d", size_group);
-  trial1->AppendGroup(group1, FieldTrial::kAllRemainingProbability);
+  trial1->AppendGroup(group1, base::FieldTrial::kAllRemainingProbability);
 
-  scoped_refptr<FieldTrial> trial2 = new FieldTrial("CacheThrottle", 100);
+  scoped_refptr<base::FieldTrial> trial2 = new base::FieldTrial("CacheThrottle", 100);
   int group2a = trial2->AppendGroup("CacheThrottle_On", 10);  // 10 % in.
   trial2->AppendGroup("CacheThrottle_Off", 10);  // 10 % control.
 
@@ -1235,9 +1236,9 @@ void BackendImpl::OnOperationCompleted(base::TimeDelta elapsed_time) {
   if (cache_type() != net::DISK_CACHE)
     return;
 
-  UMA_HISTOGRAM_TIMES(
-      FieldTrial::MakeName("DiskCache.TotalIOTime", "CacheThrottle").data(),
-      elapsed_time);
+  UMA_HISTOGRAM_TIMES(base::FieldTrial::MakeName("DiskCache.TotalIOTime",
+                                                 "CacheThrottle").data(),
+                      elapsed_time);
 
   if (!throttle_requests_)
     return;
diff --git a/net/disk_cache/block_files.cc b/net/disk_cache/block_files.cc
index 2b849fc..9d5de62 100644
--- a/net/disk_cache/block_files.cc
+++ b/net/disk_cache/block_files.cc
@@ -5,7 +5,7 @@
 #include "net/disk_cache/block_files.h"
 
 #include "base/file_util.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/thread_checker.h"
diff --git a/net/disk_cache/entry_impl.cc b/net/disk_cache/entry_impl.cc
index 24796ea..7fabbe5 100644
--- a/net/disk_cache/entry_impl.cc
+++ b/net/disk_cache/entry_impl.cc
@@ -4,8 +4,8 @@
 
 #include "net/disk_cache/entry_impl.h"
 
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
diff --git a/net/disk_cache/histogram_macros.h b/net/disk_cache/histogram_macros.h
index 2505a8a..044302c 100644
--- a/net/disk_cache/histogram_macros.h
+++ b/net/disk_cache/histogram_macros.h
@@ -20,10 +20,11 @@
 
 #define CACHE_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, bucket_count) \
     do { \
-      static scoped_refptr<Histogram> counter; \
+      static scoped_refptr<base::Histogram> counter; \
       if (!counter || name != counter->histogram_name()) \
-        counter = Histogram::FactoryGet(name, min, max, bucket_count, \
-                                        Histogram::kUmaTargetedHistogramFlag); \
+        counter = base::Histogram::FactoryGet( \
+            name, min, max, bucket_count, \
+            base::Histogram::kUmaTargetedHistogramFlag); \
       counter->Add(sample); \
     } while (0)
 
@@ -38,10 +39,11 @@
 
 #define CACHE_HISTOGRAM_CUSTOM_TIMES(name, sample, min, max, bucket_count) \
     do { \
-      static scoped_refptr<Histogram> counter; \
+      static scoped_refptr<base::Histogram> counter; \
       if (!counter || name != counter->histogram_name()) \
-        counter = Histogram::FactoryTimeGet(name, min, max, bucket_count, \
-                      Histogram::kUmaTargetedHistogramFlag); \
+        counter = base::Histogram::FactoryTimeGet( \
+            name, min, max, bucket_count, \
+            base::Histogram::kUmaTargetedHistogramFlag); \
       counter->AddTime(sample); \
     } while (0)
 
@@ -50,11 +52,11 @@
     base::TimeDelta::FromSeconds(10), 50)
 
 #define CACHE_HISTOGRAM_ENUMERATION(name, sample, boundary_value) do { \
-    static scoped_refptr<Histogram> counter; \
+    static scoped_refptr<base::Histogram> counter; \
     if (!counter || name != counter->histogram_name()) \
-      counter = LinearHistogram::FactoryGet( \
+      counter = base::LinearHistogram::FactoryGet( \
                     name, 1, boundary_value, boundary_value + 1, \
-                    Histogram::kUmaTargetedHistogramFlag); \
+                    base::Histogram::kUmaTargetedHistogramFlag); \
     counter->Add(sample); \
   } while (0)
 
@@ -70,12 +72,13 @@
 // HISTOGRAM_AGE will collect time elapsed since |initial_time|, with a
 // granularity of hours and normal values of a few months.
 #define CACHE_HISTOGRAM_AGE(name, initial_time) \
-    CACHE_HISTOGRAM_COUNTS_10000(name, (Time::Now() - initial_time).InHours())
+    CACHE_HISTOGRAM_COUNTS_10000(name, \
+                                 (base::Time::Now() - initial_time).InHours())
 
 // HISTOGRAM_AGE_MS will collect time elapsed since |initial_time|, with the
 // normal resolution of the UMA_HISTOGRAM_TIMES.
 #define CACHE_HISTOGRAM_AGE_MS(name, initial_time)\
-    CACHE_HISTOGRAM_TIMES(name, TimeTicks::Now() - initial_time)
+    CACHE_HISTOGRAM_TIMES(name, base::TimeTicks::Now() - initial_time)
 
 #define CACHE_HISTOGRAM_CACHE_ERROR(name, sample) \
     CACHE_HISTOGRAM_ENUMERATION(name, sample, 50)
diff --git a/net/disk_cache/rankings.cc b/net/disk_cache/rankings.cc
index 5c0313b..1e9e06b 100644
--- a/net/disk_cache/rankings.cc
+++ b/net/disk_cache/rankings.cc
@@ -4,7 +4,7 @@
 
 #include "net/disk_cache/rankings.h"
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "net/disk_cache/backend_impl.h"
 #include "net/disk_cache/entry_impl.h"
 #include "net/disk_cache/errors.h"
diff --git a/net/disk_cache/stats_histogram.cc b/net/disk_cache/stats_histogram.cc
index e6eaf90..06ed1b3 100644
--- a/net/disk_cache/stats_histogram.cc
+++ b/net/disk_cache/stats_histogram.cc
@@ -9,6 +9,9 @@
 
 namespace disk_cache {
 
+using base::Histogram;
+using base::StatisticsRecorder;
+
 // Static.
 const Stats* StatsHistogram::stats_ = NULL;
 
diff --git a/net/disk_cache/stats_histogram.h b/net/disk_cache/stats_histogram.h
index 1c2e15a..cbd8f03 100644
--- a/net/disk_cache/stats_histogram.h
+++ b/net/disk_cache/stats_histogram.h
@@ -8,7 +8,7 @@
 
 #include <string>
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 
 namespace disk_cache {
 
@@ -21,7 +21,7 @@ class Stats;
 // Class derivation of Histogram "deprecated," and should not be copied, and
 // may eventually go away.
 //
-class StatsHistogram : public Histogram {
+class StatsHistogram : public base::Histogram {
  public:
   class StatsSamples : public SampleSet {
    public:
@@ -46,8 +46,6 @@ class StatsHistogram : public Histogram {
   virtual void SnapshotSample(SampleSet* sample) const;
 
  private:
-  friend class Histogram;
-
   bool init_;
   static const Stats* stats_;
   DISALLOW_COPY_AND_ASSIGN(StatsHistogram);
diff --git a/net/ftp/ftp_network_transaction.cc b/net/ftp/ftp_network_transaction.cc
index 8812843..7197ae9b 100644
--- a/net/ftp/ftp_network_transaction.cc
+++ b/net/ftp/ftp_network_transaction.cc
@@ -5,7 +5,7 @@
 #include "net/ftp/ftp_network_transaction.h"
 
 #include "base/compiler_specific.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
diff --git a/net/ftp/ftp_server_type_histograms.cc b/net/ftp/ftp_server_type_histograms.cc
index de90d72..591545b 100644
--- a/net/ftp/ftp_server_type_histograms.cc
+++ b/net/ftp/ftp_server_type_histograms.cc
@@ -4,7 +4,7 @@
 
 #include "net/ftp/ftp_server_type_histograms.h"
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 
 namespace net {
 
diff --git a/net/http/http_auth_controller.cc b/net/http/http_auth_controller.cc
index 736ffa9..545ae2a 100644
--- a/net/http/http_auth_controller.cc
+++ b/net/http/http_auth_controller.cc
@@ -4,7 +4,7 @@
 
 #include "net/http/http_auth_controller.h"
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "net/base/auth.h"
diff --git a/net/http/http_auth_handler.cc b/net/http/http_auth_handler.cc
index ccb8766..d6e6a62 100644
--- a/net/http/http_auth_handler.cc
+++ b/net/http/http_auth_handler.cc
@@ -4,8 +4,8 @@
 
 #include "net/http/http_auth_handler.h"
 
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "net/base/net_errors.h"
@@ -52,11 +52,11 @@ bool HttpAuthHandler::InitFromChallenge(
   DCHECK(!ok || properties_ != -1);
 
   if (ok)
-    histogram_ = Histogram::FactoryTimeGet(
+    histogram_ = base::Histogram::FactoryTimeGet(
         GenerateHistogramNameFromScheme(scheme()),
         base::TimeDelta::FromMilliseconds(1),
         base::TimeDelta::FromSeconds(10), 50,
-        Histogram::kUmaTargetedHistogramFlag);
+        base::Histogram::kUmaTargetedHistogramFlag);
 
   return ok;
 }
diff --git a/net/http/http_auth_handler.h b/net/http/http_auth_handler.h
index 4c03a01..908b065 100644
--- a/net/http/http_auth_handler.h
+++ b/net/http/http_auth_handler.h
@@ -14,7 +14,9 @@
 #include "net/base/net_log.h"
 #include "net/http/http_auth.h"
 
+namespace base {
 class Histogram;
+}
 
 namespace net {
 
@@ -187,7 +189,7 @@ class HttpAuthHandler {
   CompletionCallbackImpl<HttpAuthHandler> wrapper_callback_;
   // When GenerateAuthToken was called.
   base::TimeTicks generate_auth_token_start_;
-  scoped_refptr<Histogram> histogram_;
+  scoped_refptr<base::Histogram> histogram_;
 };
 
 }  // namespace net
diff --git a/net/http/http_cache_transaction.cc b/net/http/http_cache_transaction.cc
index 138cd13..5d05616 100644
--- a/net/http/http_cache_transaction.cc
+++ b/net/http/http_cache_transaction.cc
@@ -13,8 +13,8 @@
 #include <string>
 
 #include "base/compiler_specific.h"
-#include "base/field_trial.h"
-#include "base/histogram.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
 #include "base/ref_counted.h"
 #include "base/string_util.h"
 #include "base/time.h"
@@ -856,11 +856,11 @@ int HttpCache::Transaction::DoAddToEntryComplete(int result) {
       base::TimeTicks::Now() - entry_lock_waiting_since_;
   UMA_HISTOGRAM_TIMES("HttpCache.EntryLockWait", entry_lock_wait);
   static const bool prefetching_fieldtrial =
-      FieldTrialList::Find("Prefetch") &&
-      !FieldTrialList::Find("Prefetch")->group_name().empty();
+      base::FieldTrialList::Find("Prefetch") &&
+      !base::FieldTrialList::Find("Prefetch")->group_name().empty();
   if (prefetching_fieldtrial) {
     UMA_HISTOGRAM_TIMES(
-        FieldTrial::MakeName("HttpCache.EntryLockWait", "Prefetch"),
+        base::FieldTrial::MakeName("HttpCache.EntryLockWait", "Prefetch"),
         entry_lock_wait);
   }
 
diff --git a/net/http/http_network_layer.cc b/net/http/http_network_layer.cc
index cf93500..38f95ef 100644
--- a/net/http/http_network_layer.cc
+++ b/net/http/http_network_layer.cc
@@ -4,7 +4,6 @@
 
 #include "net/http/http_network_layer.h"
 
-#include "base/field_trial.h"
 #include "base/logging.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
diff --git a/net/http/http_network_transaction.cc b/net/http/http_network_transaction.cc
index 8ef9aca..bf1c0e9 100644
--- a/net/http/http_network_transaction.cc
+++ b/net/http/http_network_transaction.cc
@@ -8,11 +8,11 @@
 #include <vector>
 
 #include "base/compiler_specific.h"
-#include "base/field_trial.h"
 #include "base/format_macros.h"
-#include "base/histogram.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/stats_counters.h"
 #include "base/scoped_ptr.h"
-#include "base/stats_counters.h"
 #include "base/stl_util-inl.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
@@ -976,11 +976,11 @@ void HttpNetworkTransaction::LogTransactionConnectedMetrics() {
         100);
 
   static bool use_conn_impact_histogram(
-      FieldTrialList::Find("ConnCountImpact") &&
-      !FieldTrialList::Find("ConnCountImpact")->group_name().empty());
+      base::FieldTrialList::Find("ConnCountImpact") &&
+      !base::FieldTrialList::Find("ConnCountImpact")->group_name().empty());
   if (use_conn_impact_histogram) {
     UMA_HISTOGRAM_CLIPPED_TIMES(
-        FieldTrial::MakeName("Net.Transaction_Connected_New",
+        base::FieldTrial::MakeName("Net.Transaction_Connected_New",
             "ConnCountImpact"),
         total_duration,
         base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(10),
@@ -988,17 +988,19 @@ void HttpNetworkTransaction::LogTransactionConnectedMetrics() {
     }
   }
 
-  static bool use_spdy_histogram(FieldTrialList::Find("SpdyImpact") &&
-      !FieldTrialList::Find("SpdyImpact")->group_name().empty());
+  static bool use_spdy_histogram(base::FieldTrialList::Find("SpdyImpact") &&
+      !base::FieldTrialList::Find("SpdyImpact")->group_name().empty());
   if (use_spdy_histogram && response_.was_npn_negotiated) {
     UMA_HISTOGRAM_CLIPPED_TIMES(
-      FieldTrial::MakeName("Net.Transaction_Connected_Under_10", "SpdyImpact"),
+      base::FieldTrial::MakeName("Net.Transaction_Connected_Under_10",
+                                 "SpdyImpact"),
         total_duration, base::TimeDelta::FromMilliseconds(1),
         base::TimeDelta::FromMinutes(10), 100);
 
     if (!reused_socket) {
       UMA_HISTOGRAM_CLIPPED_TIMES(
-          FieldTrial::MakeName("Net.Transaction_Connected_New", "SpdyImpact"),
+          base::FieldTrial::MakeName("Net.Transaction_Connected_New",
+                                     "SpdyImpact"),
           total_duration, base::TimeDelta::FromMilliseconds(1),
           base::TimeDelta::FromMinutes(10), 100);
     }
diff --git a/net/http/http_stream_parser.cc b/net/http/http_stream_parser.cc
index 512f509..0e7610c 100644
--- a/net/http/http_stream_parser.cc
+++ b/net/http/http_stream_parser.cc
@@ -5,7 +5,7 @@
 #include "net/http/http_stream_parser.h"
 
 #include "base/compiler_specific.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "net/base/auth.h"
 #include "net/base/io_buffer.h"
 #include "net/base/ssl_cert_request_info.h"
diff --git a/net/ocsp/nss_ocsp.cc b/net/ocsp/nss_ocsp.cc
index 3faeb54..fbb734f 100644
--- a/net/ocsp/nss_ocsp.cc
+++ b/net/ocsp/nss_ocsp.cc
@@ -17,11 +17,11 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/condition_variable.h"
-#include "base/histogram.h"
 #include "base/lazy_instance.h"
 #include "base/lock.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/thread.h"
diff --git a/net/proxy/proxy_resolver_winhttp.cc b/net/proxy/proxy_resolver_winhttp.cc
index 4307b5e..962271f 100644
--- a/net/proxy/proxy_resolver_winhttp.cc
+++ b/net/proxy/proxy_resolver_winhttp.cc
@@ -7,7 +7,7 @@
 #include <windows.h>
 #include <winhttp.h>
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "googleurl/src/gurl.h"
diff --git a/net/proxy/proxy_service.cc b/net/proxy/proxy_service.cc
index 2884d27..632e63b 100644
--- a/net/proxy/proxy_service.cc
+++ b/net/proxy/proxy_service.cc
@@ -9,7 +9,6 @@
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/values.h"
-#include "base/histogram.h"
 #include "base/message_loop.h"
 #include "base/string_util.h"
 #include "googleurl/src/gurl.h"
diff --git a/net/socket/client_socket.cc b/net/socket/client_socket.cc
index 0edee70..8be3ae1 100644
--- a/net/socket/client_socket.cc
+++ b/net/socket/client_socket.cc
@@ -4,8 +4,8 @@
 
 #include "net/socket/client_socket.h"
 
-#include "base/field_trial.h"
-#include "base/histogram.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
 
 namespace net {
 
@@ -46,12 +46,12 @@ void ClientSocket::UseHistory::EmitPreconnectionHistograms() const {
   UMA_HISTOGRAM_ENUMERATION("Net.PreconnectUtilization2", result, 9);
 
   static const bool connect_backup_jobs_fieldtrial =
-      FieldTrialList::Find("ConnnectBackupJobs") &&
-      !FieldTrialList::Find("ConnnectBackupJobs")->group_name().empty();
+      base::FieldTrialList::Find("ConnnectBackupJobs") &&
+      !base::FieldTrialList::Find("ConnnectBackupJobs")->group_name().empty();
   if (connect_backup_jobs_fieldtrial) {
     UMA_HISTOGRAM_ENUMERATION(
-        FieldTrial::MakeName("Net.PreconnectUtilization2",
-                             "ConnnectBackupJobs"),
+        base::FieldTrial::MakeName("Net.PreconnectUtilization2",
+                                   "ConnnectBackupJobs"),
         result, 9);
   }
 }
diff --git a/net/socket/client_socket_handle.cc b/net/socket/client_socket_handle.cc
index f9ab8985..6184905 100644
--- a/net/socket/client_socket_handle.cc
+++ b/net/socket/client_socket_handle.cc
@@ -5,7 +5,7 @@
 #include "net/socket/client_socket_handle.h"
 
 #include "base/compiler_specific.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/logging.h"
 #include "net/base/net_errors.h"
 #include "net/socket/client_socket_pool.h"
diff --git a/net/socket/client_socket_pool_base.cc b/net/socket/client_socket_pool_base.cc
index 13d8b68..75abae6d 100644
--- a/net/socket/client_socket_pool_base.cc
+++ b/net/socket/client_socket_pool_base.cc
@@ -7,7 +7,7 @@
 #include "base/compiler_specific.h"
 #include "base/format_macros.h"
 #include "base/message_loop.h"
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
 #include "base/time.h"
diff --git a/net/socket/client_socket_pool_histograms.cc b/net/socket/client_socket_pool_histograms.cc
index 873bd5b..202112b 100644
--- a/net/socket/client_socket_pool_histograms.cc
+++ b/net/socket/client_socket_pool_histograms.cc
@@ -6,12 +6,15 @@
 
 #include <string>
 
-#include "base/field_trial.h"
-#include "base/histogram.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
 #include "net/socket/client_socket_handle.h"
 
 namespace net {
 
+using base::Histogram;
+using base::LinearHistogram;
+
 ClientSocketPoolHistograms::ClientSocketPoolHistograms(
     const std::string& pool_name)
     : is_http_proxy_connection_(false),
@@ -56,11 +59,12 @@ void ClientSocketPoolHistograms::AddRequestTime(base::TimeDelta time) const {
   request_time_->AddTime(time);
 
   static bool proxy_connection_impact_trial_exists(
-      FieldTrialList::Find("ProxyConnectionImpact") &&
-      !FieldTrialList::Find("ProxyConnectionImpact")->group_name().empty());
+      base::FieldTrialList::Find("ProxyConnectionImpact") &&
+      !base::FieldTrialList::Find("ProxyConnectionImpact")->
+          group_name().empty());
   if (proxy_connection_impact_trial_exists && is_http_proxy_connection_) {
     UMA_HISTOGRAM_CUSTOM_TIMES(
-        FieldTrial::MakeName("Net.HttpProxySocketRequestTime",
+        base::FieldTrial::MakeName("Net.HttpProxySocketRequestTime",
                              "ProxyConnectionImpact"),
         time,
         base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(10),
@@ -68,7 +72,7 @@ void ClientSocketPoolHistograms::AddRequestTime(base::TimeDelta time) const {
   }
   if (proxy_connection_impact_trial_exists && is_socks_connection_) {
     UMA_HISTOGRAM_CUSTOM_TIMES(
-        FieldTrial::MakeName("Net.SocksSocketRequestTime",
+        base::FieldTrial::MakeName("Net.SocksSocketRequestTime",
                              "ProxyConnectionImpact"),
         time,
         base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(10),
diff --git a/net/socket/client_socket_pool_histograms.h b/net/socket/client_socket_pool_histograms.h
index 41aad57..ace8a0d 100644
--- a/net/socket/client_socket_pool_histograms.h
+++ b/net/socket/client_socket_pool_histograms.h
@@ -11,7 +11,9 @@
 #include "base/time.h"
 #include "base/ref_counted.h"
 
+namespace base {
 class Histogram;
+}
 
 namespace net {
 
@@ -26,10 +28,10 @@ class ClientSocketPoolHistograms {
   void AddReusedIdleTime(base::TimeDelta time) const;
 
  private:
-  scoped_refptr<Histogram> socket_type_;
-  scoped_refptr<Histogram> request_time_;
-  scoped_refptr<Histogram> unused_idle_time_;
-  scoped_refptr<Histogram> reused_idle_time_;
+  scoped_refptr<base::Histogram> socket_type_;
+  scoped_refptr<base::Histogram> request_time_;
+  scoped_refptr<base::Histogram> unused_idle_time_;
+  scoped_refptr<base::Histogram> reused_idle_time_;
 
   bool is_http_proxy_connection_;
   bool is_socks_connection_;
diff --git a/net/socket/ssl_client_socket_nss.cc b/net/socket/ssl_client_socket_nss.cc
index ba135e1..aa8c7fc 100644
--- a/net/socket/ssl_client_socket_nss.cc
+++ b/net/socket/ssl_client_socket_nss.cc
@@ -64,7 +64,7 @@
 #include <limits>
 
 #include "base/compiler_specific.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/logging.h"
 #include "base/nss_util.h"
 #include "base/singleton.h"
diff --git a/net/socket/ssl_client_socket_openssl.cc b/net/socket/ssl_client_socket_openssl.cc
index 4ff1b48..64852f2 100644
--- a/net/socket/ssl_client_socket_openssl.cc
+++ b/net/socket/ssl_client_socket_openssl.cc
@@ -11,7 +11,7 @@
 #include <openssl/err.h>
 
 #include "net/base/cert_verifier.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "net/base/net_errors.h"
 #include "net/base/openssl_util.h"
 #include "net/base/ssl_connection_status_flags.h"
diff --git a/net/socket/ssl_client_socket_pool.cc b/net/socket/ssl_client_socket_pool.cc
index 22d921a..a338a7f 100644
--- a/net/socket/ssl_client_socket_pool.cc
+++ b/net/socket/ssl_client_socket_pool.cc
@@ -4,7 +4,7 @@
 
 #include "net/socket/ssl_client_socket_pool.h"
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/values.h"
 #include "net/base/net_errors.h"
 #include "net/base/ssl_cert_request_info.h"
@@ -316,18 +316,19 @@ int SSLConnectJob::DoSSLConnectComplete(int result) {
     DCHECK(ssl_connect_start_time_ != base::TimeTicks());
     base::TimeDelta connect_duration =
         base::TimeTicks::Now() - ssl_connect_start_time_;
-    if (using_spdy)
+    if (using_spdy) {
       UMA_HISTOGRAM_CUSTOM_TIMES("Net.SpdyConnectionLatency",
                                  connect_duration,
                                  base::TimeDelta::FromMilliseconds(1),
                                  base::TimeDelta::FromMinutes(10),
                                  100);
-    else
+    } else {
       UMA_HISTOGRAM_CUSTOM_TIMES("Net.SSL_Connection_Latency",
                                  connect_duration,
                                  base::TimeDelta::FromMilliseconds(1),
                                  base::TimeDelta::FromMinutes(10),
                                  100);
+    }
   }
 
   if (result == OK || IsCertificateError(result)) {
diff --git a/net/socket/tcp_client_socket_libevent.cc b/net/socket/tcp_client_socket_libevent.cc
index 889bfc0..86d6afe9 100644
--- a/net/socket/tcp_client_socket_libevent.cc
+++ b/net/socket/tcp_client_socket_libevent.cc
@@ -16,7 +16,7 @@
 #include "base/eintr_wrapper.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
 #include "base/string_util.h"
 #include "net/base/address_list_net_log_param.h"
 #include "net/base/io_buffer.h"
@@ -139,7 +139,7 @@ int TCPClientSocketLibevent::Connect(CompletionCallback* callback) {
   if (socket_ != kInvalidSocket)
     return OK;
 
-  static StatsCounter connects("tcp.connect");
+  static base::StatsCounter connects("tcp.connect");
   connects.Increment();
 
   DCHECK(!waiting_connect());
@@ -328,7 +328,7 @@ int TCPClientSocketLibevent::Read(IOBuffer* buf,
 
   int nread = HANDLE_EINTR(read(socket_, buf->data(), buf_len));
   if (nread >= 0) {
-    static StatsCounter read_bytes("tcp.read_bytes");
+    static base::StatsCounter read_bytes("tcp.read_bytes");
     read_bytes.Add(nread);
     if (nread > 0)
       use_history_.set_was_used_to_convey_data();
@@ -367,7 +367,7 @@ int TCPClientSocketLibevent::Write(IOBuffer* buf,
 
   int nwrite = HANDLE_EINTR(write(socket_, buf->data(), buf_len));
   if (nwrite >= 0) {
-    static StatsCounter write_bytes("tcp.write_bytes");
+    static base::StatsCounter write_bytes("tcp.write_bytes");
     write_bytes.Add(nwrite);
     if (nwrite > 0)
       use_history_.set_was_used_to_convey_data();
@@ -487,7 +487,7 @@ void TCPClientSocketLibevent::DidCompleteRead() {
   int result;
   if (bytes_transferred >= 0) {
     result = bytes_transferred;
-    static StatsCounter read_bytes("tcp.read_bytes");
+    static base::StatsCounter read_bytes("tcp.read_bytes");
     read_bytes.Add(bytes_transferred);
     if (bytes_transferred > 0)
       use_history_.set_was_used_to_convey_data();
@@ -514,7 +514,7 @@ void TCPClientSocketLibevent::DidCompleteWrite() {
   int result;
   if (bytes_transferred >= 0) {
     result = bytes_transferred;
-    static StatsCounter write_bytes("tcp.write_bytes");
+    static base::StatsCounter write_bytes("tcp.write_bytes");
     write_bytes.Add(bytes_transferred);
     if (bytes_transferred > 0)
       use_history_.set_was_used_to_convey_data();
diff --git a/net/socket/tcp_client_socket_pool.cc b/net/socket/tcp_client_socket_pool.cc
index f11ae25..820f58e 100644
--- a/net/socket/tcp_client_socket_pool.cc
+++ b/net/socket/tcp_client_socket_pool.cc
@@ -5,9 +5,9 @@
 #include "net/socket/tcp_client_socket_pool.h"
 
 #include "base/compiler_specific.h"
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/time.h"
 #include "net/base/net_log.h"
diff --git a/net/socket/tcp_client_socket_win.cc b/net/socket/tcp_client_socket_win.cc
index 0275f18..9bbb034 100644
--- a/net/socket/tcp_client_socket_win.cc
+++ b/net/socket/tcp_client_socket_win.cc
@@ -7,7 +7,7 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory_debug.h"
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
 #include "base/string_util.h"
 #include "base/sys_info.h"
 #include "net/base/address_list_net_log_param.h"
@@ -311,7 +311,7 @@ int TCPClientSocketWin::Connect(CompletionCallback* callback) {
   if (socket_ != INVALID_SOCKET)
     return OK;
 
-  static StatsCounter connects("tcp.connect");
+  static base::StatsCounter connects("tcp.connect");
   connects.Increment();
 
   net_log_.BeginEvent(NetLog::TYPE_TCP_CONNECT,
@@ -564,7 +564,7 @@ int TCPClientSocketWin::Read(IOBuffer* buf,
       // false error reports.
       // See bug 5297.
       base::MemoryDebug::MarkAsInitialized(core_->read_buffer_.buf, num);
-      static StatsCounter read_bytes("tcp.read_bytes");
+      static base::StatsCounter read_bytes("tcp.read_bytes");
       read_bytes.Add(num);
       if (num > 0)
         use_history_.set_was_used_to_convey_data();
@@ -594,7 +594,7 @@ int TCPClientSocketWin::Write(IOBuffer* buf,
   DCHECK_GT(buf_len, 0);
   DCHECK(!core_->write_iobuffer_);
 
-  static StatsCounter writes("tcp.writes");
+  static base::StatsCounter writes("tcp.writes");
   writes.Increment();
 
   core_->write_buffer_.len = buf_len;
@@ -616,7 +616,7 @@ int TCPClientSocketWin::Write(IOBuffer* buf,
                    << " bytes, but " << rv << " bytes reported.";
         return ERR_WINSOCK_UNEXPECTED_WRITTEN_BYTES;
       }
-      static StatsCounter write_bytes("tcp.write_bytes");
+      static base::StatsCounter write_bytes("tcp.write_bytes");
       write_bytes.Add(rv);
       if (rv > 0)
         use_history_.set_was_used_to_convey_data();
@@ -777,7 +777,7 @@ void TCPClientSocketWin::DidCompleteRead() {
   waiting_read_ = false;
   core_->read_iobuffer_ = NULL;
   if (ok) {
-    static StatsCounter read_bytes("tcp.read_bytes");
+    static base::StatsCounter read_bytes("tcp.read_bytes");
     read_bytes.Add(num_bytes);
     if (num_bytes > 0)
       use_history_.set_was_used_to_convey_data();
@@ -808,7 +808,7 @@ void TCPClientSocketWin::DidCompleteWrite() {
                  << " bytes reported.";
       rv = ERR_WINSOCK_UNEXPECTED_WRITTEN_BYTES;
     } else {
-      static StatsCounter write_bytes("tcp.write_bytes");
+      static base::StatsCounter write_bytes("tcp.write_bytes");
       write_bytes.Add(num_bytes);
       if (num_bytes > 0)
         use_history_.set_was_used_to_convey_data();
diff --git a/net/socket_stream/socket_stream_metrics.cc b/net/socket_stream/socket_stream_metrics.cc
index 71239af..108e829 100644
--- a/net/socket_stream/socket_stream_metrics.cc
+++ b/net/socket_stream/socket_stream_metrics.cc
@@ -6,7 +6,7 @@
 
 #include <string.h>
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "googleurl/src/gurl.h"
 
diff --git a/net/socket_stream/socket_stream_metrics_unittest.cc b/net/socket_stream/socket_stream_metrics_unittest.cc
index 7d44f79..64718e3 100644
--- a/net/socket_stream/socket_stream_metrics_unittest.cc
+++ b/net/socket_stream/socket_stream_metrics_unittest.cc
@@ -3,12 +3,15 @@
 // found in the LICENSE file.
 
 #include "base/basictypes.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "googleurl/src/gurl.h"
 #include "net/socket_stream/socket_stream_metrics.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 
+using base::Histogram;
+using base::StatisticsRecorder;
+
 namespace net {
 
 TEST(SocketStreamMetricsTest, Initialize) {
diff --git a/net/spdy/spdy_framer.cc b/net/spdy/spdy_framer.cc
index b10eee8..af8e305 100644
--- a/net/spdy/spdy_framer.cc
+++ b/net/spdy/spdy_framer.cc
@@ -4,9 +4,8 @@
 
 #include "net/spdy/spdy_framer.h"
 
+#include "base/metrics/stats_counters.h"
 #include "base/scoped_ptr.h"
-#include "base/stats_counters.h"
-
 #include "net/spdy/spdy_frame_builder.h"
 #include "net/spdy/spdy_bitmasks.h"
 
@@ -915,9 +914,9 @@ SpdyFrame* SpdyFramer::CompressFrameWithZStream(const SpdyFrame& frame,
   int header_length;
   const char* payload;
 
-  static StatsCounter compressed_frames("spdy.CompressedFrames");
-  static StatsCounter pre_compress_bytes("spdy.PreCompressSize");
-  static StatsCounter post_compress_bytes("spdy.PostCompressSize");
+  static base::StatsCounter compressed_frames("spdy.CompressedFrames");
+  static base::StatsCounter pre_compress_bytes("spdy.PreCompressSize");
+  static base::StatsCounter post_compress_bytes("spdy.PostCompressSize");
 
   if (!enable_compression_)
     return DuplicateFrame(frame);
@@ -968,9 +967,9 @@ SpdyFrame* SpdyFramer::DecompressFrameWithZStream(const SpdyFrame& frame,
   int header_length;
   const char* payload;
 
-  static StatsCounter decompressed_frames("spdy.DecompressedFrames");
-  static StatsCounter pre_decompress_bytes("spdy.PreDeCompressSize");
-  static StatsCounter post_decompress_bytes("spdy.PostDeCompressSize");
+  static base::StatsCounter decompressed_frames("spdy.DecompressedFrames");
+  static base::StatsCounter pre_decompress_bytes("spdy.PreDeCompressSize");
+  static base::StatsCounter post_decompress_bytes("spdy.PostDeCompressSize");
 
   if (!enable_compression_)
     return DuplicateFrame(frame);
diff --git a/net/spdy/spdy_session.cc b/net/spdy/spdy_session.cc
index d0ebff9..3967a81 100644
--- a/net/spdy/spdy_session.cc
+++ b/net/spdy/spdy_session.cc
@@ -8,7 +8,7 @@
 #include "base/linked_ptr.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
 #include "base/stl_util-inl.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
@@ -284,7 +284,7 @@ net::Error SpdySession::InitializeWithSocket(
     ClientSocketHandle* connection,
     bool is_secure,
     int certificate_error_code) {
-  static StatsCounter spdy_sessions("spdy.sessions");
+  static base::StatsCounter spdy_sessions("spdy.sessions");
   spdy_sessions.Increment();
 
   AdjustSocketBufferSizes(connection->socket());
@@ -452,7 +452,7 @@ int SpdySession::WriteSynStream(
           flags, false, headers.get()));
   QueueFrame(syn_frame.get(), priority, stream);
 
-  static StatsCounter spdy_requests("spdy.requests");
+  static base::StatsCounter spdy_requests("spdy.requests");
   spdy_requests.Increment();
   streams_initiated_count_++;
 
@@ -766,8 +766,9 @@ void SpdySession::WriteSocket() {
 }
 
 void SpdySession::CloseAllStreams(net::Error status) {
-  static StatsCounter abandoned_streams("spdy.abandoned_streams");
-  static StatsCounter abandoned_push_streams("spdy.abandoned_push_streams");
+  static base::StatsCounter abandoned_streams("spdy.abandoned_streams");
+  static base::StatsCounter abandoned_push_streams(
+      "spdy.abandoned_push_streams");
 
   if (!active_streams_.empty())
     abandoned_streams.Add(active_streams_.size());
@@ -914,7 +915,7 @@ void SpdySession::RemoveFromPool() {
 
 scoped_refptr<SpdyStream> SpdySession::GetActivePushStream(
     const std::string& path) {
-  static StatsCounter used_push_streams("spdy.claimed_push_streams");
+  static base::StatsCounter used_push_streams("spdy.claimed_push_streams");
 
   PushedStreamMap::iterator it = unclaimed_pushed_streams_.find(path);
   if (it != unclaimed_pushed_streams_.end()) {
@@ -1063,7 +1064,7 @@ void SpdySession::OnSyn(const spdy::SpdySynStreamControlFrame& frame,
   if (!Respond(*headers, stream))
     return;
 
-  static StatsCounter push_requests("spdy.pushed_streams");
+  static base::StatsCounter push_requests("spdy.pushed_streams");
   push_requests.Increment();
 }
 
diff --git a/net/tools/fetch/fetch_client.cc b/net/tools/fetch/fetch_client.cc
index 14f7afb..b976ce2 100644
--- a/net/tools/fetch/fetch_client.cc
+++ b/net/tools/fetch/fetch_client.cc
@@ -7,8 +7,8 @@
 #include "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_counters.h"
 #include "base/singleton.h"
-#include "base/stats_counters.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "net/base/completion_callback.h"
@@ -86,7 +86,7 @@ class Client {
     }
 
     // Deal with received data here.
-    static StatsCounter bytes_read("FetchClient.bytes_read");
+    static base::StatsCounter bytes_read("FetchClient.bytes_read");
     bytes_read.Add(result);
 
     // Issue a read for more data.
@@ -99,7 +99,7 @@ class Client {
   }
 
   void OnRequestComplete(int result) {
-    static StatsCounter requests("FetchClient.requests");
+    static base::StatsCounter requests("FetchClient.requests");
     requests.Increment();
     driver_->ClientStopped();
     printf(".");
@@ -117,7 +117,7 @@ class Client {
 
 int main(int argc, char**argv) {
   base::AtExitManager exit;
-  StatsTable table("fetchclient", 50, 1000);
+  base::StatsTable table("fetchclient", 50, 1000);
   table.set_current(&table);
 
   CommandLine::Init(argc, argv);
@@ -163,8 +163,8 @@ int main(int argc, char**argv) {
   }
 
   {
-    StatsCounterTimer driver_time("FetchClient.total_time");
-    StatsScope<StatsCounterTimer> scope(driver_time);
+    base::StatsCounterTimer driver_time("FetchClient.total_time");
+    base::StatsScope<base::StatsCounterTimer> scope(driver_time);
 
     Client** clients = new Client*[client_limit];
     for (int i = 0; i < client_limit; i++)
diff --git a/net/tools/fetch/fetch_server.cc b/net/tools/fetch/fetch_server.cc
index 085bd46..ca058f1 100644
--- a/net/tools/fetch/fetch_server.cc
+++ b/net/tools/fetch/fetch_server.cc
@@ -1,12 +1,12 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_counters.h"
 #include "base/singleton.h"
-#include "base/stats_counters.h"
 #include "net/base/completion_callback.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
@@ -24,7 +24,7 @@ void usage(const char* program_name) {
 
 int main(int argc, char**argv) {
   base::AtExitManager exit;
-  StatsTable table("fetchserver", 50, 1000);
+  base::StatsTable table("fetchserver", 50, 1000);
   table.set_current(&table);
 
 #if defined(OS_WIN)
diff --git a/net/url_request/url_request.cc b/net/url_request/url_request.cc
index b4f9d51..ee52e0a 100644
--- a/net/url_request/url_request.cc
+++ b/net/url_request/url_request.cc
@@ -6,8 +6,8 @@
 
 #include "base/compiler_specific.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_counters.h"
 #include "base/singleton.h"
-#include "base/stats_counters.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_log.h"
diff --git a/net/url_request/url_request_job.cc b/net/url_request/url_request_job.cc
index 5ed3097..2a4d036 100644
--- a/net/url_request/url_request_job.cc
+++ b/net/url_request/url_request_job.cc
@@ -4,8 +4,8 @@
 
 #include "net/url_request/url_request_job.h"
 
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "net/base/auth.h"
diff --git a/printing/emf_win.cc b/printing/emf_win.cc
index b7c6198..1a7c8dd 100644
--- a/printing/emf_win.cc
+++ b/printing/emf_win.cc
@@ -5,8 +5,8 @@
 #include "printing/emf_win.h"
 
 #include "base/file_path.h"
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/scoped_ptr.h"
 #include "base/time.h"
 #include "gfx/codec/jpeg_codec.h"
diff --git a/skia/ext/image_operations.cc b/skia/ext/image_operations.cc
index 10998d5..67236aa 100644
--- a/skia/ext/image_operations.cc
+++ b/skia/ext/image_operations.cc
@@ -9,8 +9,8 @@
 #include "skia/ext/image_operations.h"
 
 // TODO(pkasting): skia/ext should not depend on base/!
-#include "base/histogram.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/stack_container.h"
 #include "base/time.h"
 #include "build/build_config.h"
diff --git a/tools/memory_watcher/memory_watcher.cc b/tools/memory_watcher/memory_watcher.cc
index 6e67793..fd835cb 100644
--- a/tools/memory_watcher/memory_watcher.cc
+++ b/tools/memory_watcher/memory_watcher.cc
@@ -10,16 +10,16 @@
 #include "base/file_util.h"
 #include "base/lock.h"
 #include "base/logging.h"
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "tools/memory_watcher/call_stack.h"
 #include "tools/memory_watcher/preamble_patcher.h"
 
-static StatsCounter mem_in_use("MemoryInUse.Bytes");
-static StatsCounter mem_in_use_blocks("MemoryInUse.Blocks");
-static StatsCounter mem_in_use_allocs("MemoryInUse.Allocs");
-static StatsCounter mem_in_use_frees("MemoryInUse.Frees");
+static base::StatsCounter mem_in_use("MemoryInUse.Bytes");
+static base::StatsCounter mem_in_use_blocks("MemoryInUse.Blocks");
+static base::StatsCounter mem_in_use_allocs("MemoryInUse.Allocs");
+static base::StatsCounter mem_in_use_frees("MemoryInUse.Frees");
 
 // ---------------------------------------------------------------------
 
diff --git a/webkit/appcache/appcache_histograms.cc b/webkit/appcache/appcache_histograms.cc
index 9907047..dc8e419 100644
--- a/webkit/appcache/appcache_histograms.cc
+++ b/webkit/appcache/appcache_histograms.cc
@@ -4,7 +4,7 @@
 
 #include "webkit/appcache/appcache_histograms.h"
 
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 
 namespace appcache {
 
diff --git a/webkit/extensions/v8/benchmarking_extension.cc b/webkit/extensions/v8/benchmarking_extension.cc
index 1a30968..b7abc57 100644
--- a/webkit/extensions/v8/benchmarking_extension.cc
+++ b/webkit/extensions/v8/benchmarking_extension.cc
@@ -1,13 +1,14 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "webkit/extensions/v8/benchmarking_extension.h"
+
 #include "base/command_line.h"
-#include "base/stats_table.h"
+#include "base/metrics/stats_table.h"
 #include "base/time.h"
 #include "net/http/http_network_layer.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebCache.h"
-#include "webkit/extensions/v8/benchmarking_extension.h"
 #include "webkit/glue/webkit_glue.h"
 
 using WebKit::WebCache;
@@ -107,7 +108,7 @@ class BenchmarkingWrapper : public v8::Extension {
   }
 
   static v8::Handle<v8::Value> GetCounter(const v8::Arguments& args) {
-    if (!args.Length() || !args[0]->IsString() || !StatsTable::current())
+    if (!args.Length() || !args[0]->IsString() || !base::StatsTable::current())
       return v8::Undefined();
 
     // Extract the name argument
@@ -116,7 +117,7 @@ class BenchmarkingWrapper : public v8::Extension {
     name[1] = ':';
     args[0]->ToString()->WriteAscii(&name[2], 0, sizeof(name) - 3);
 
-    int counter = StatsTable::current()->GetCounterValue(name);
+    int counter = base::StatsTable::current()->GetCounterValue(name);
     return v8::Integer::New(counter);
   }
 
diff --git a/webkit/glue/plugins/pepper_plugin_instance.cc b/webkit/glue/plugins/pepper_plugin_instance.cc
index c051fff..30c4fb3 100644
--- a/webkit/glue/plugins/pepper_plugin_instance.cc
+++ b/webkit/glue/plugins/pepper_plugin_instance.cc
@@ -5,7 +5,7 @@
 #include "webkit/glue/plugins/pepper_plugin_instance.h"
 
 #include "base/logging.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #if defined(OS_MACOSX)
 #include "base/mac_util.h"
 #include "base/scoped_cftyperef.h"
diff --git a/webkit/glue/plugins/plugin_lib.cc b/webkit/glue/plugins/plugin_lib.cc
index 9a0770e..6c95274 100644
--- a/webkit/glue/plugins/plugin_lib.cc
+++ b/webkit/glue/plugins/plugin_lib.cc
@@ -6,7 +6,7 @@
 
 #include "base/logging.h"
 #include "base/message_loop.h"
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
 #include "base/string_util.h"
 #include "webkit/glue/webkit_glue.h"
 #include "webkit/glue/plugins/plugin_instance.h"
@@ -72,7 +72,7 @@ PluginLib::PluginLib(const WebPluginInfo& info,
       saved_data_(0),
       instance_count_(0),
       skip_unload_(false) {
-  StatsCounter(kPluginLibrariesLoadedCounter).Increment();
+  base::StatsCounter(kPluginLibrariesLoadedCounter).Increment();
   memset(static_cast<void*>(&plugin_funcs_), 0, sizeof(plugin_funcs_));
   g_loaded_libs->push_back(this);
 
@@ -87,7 +87,7 @@ PluginLib::PluginLib(const WebPluginInfo& info,
 }
 
 PluginLib::~PluginLib() {
-  StatsCounter(kPluginLibrariesLoadedCounter).Decrement();
+  base::StatsCounter(kPluginLibrariesLoadedCounter).Decrement();
   if (saved_data_ != 0) {
     // TODO - delete the savedData object here
   }
@@ -143,13 +143,13 @@ void PluginLib::PreventLibraryUnload() {
 PluginInstance* PluginLib::CreateInstance(const std::string& mime_type) {
   PluginInstance* new_instance = new PluginInstance(this, mime_type);
   instance_count_++;
-  StatsCounter(kPluginInstancesActiveCounter).Increment();
+  base::StatsCounter(kPluginInstancesActiveCounter).Increment();
   DCHECK_NE(static_cast<PluginInstance*>(NULL), new_instance);
   return new_instance;
 }
 
 void PluginLib::CloseInstance() {
-  StatsCounter(kPluginInstancesActiveCounter).Decrement();
+  base::StatsCounter(kPluginInstancesActiveCounter).Decrement();
   instance_count_--;
   // If a plugin is running in its own process it will get unloaded on process
   // shutdown.
diff --git a/webkit/glue/plugins/webplugin_delegate_impl.cc b/webkit/glue/plugins/webplugin_delegate_impl.cc
index 53745466..c54bbc8 100644
--- a/webkit/glue/plugins/webplugin_delegate_impl.cc
+++ b/webkit/glue/plugins/webplugin_delegate_impl.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -11,7 +11,6 @@
 #include "base/message_loop.h"
 #include "base/process_util.h"
 #include "base/scoped_ptr.h"
-#include "base/stats_counters.h"
 #include "base/string_util.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebInputEvent.h"
 #include "webkit/glue/plugins/plugin_constants_win.h"
diff --git a/webkit/glue/plugins/webplugin_delegate_impl_gtk.cc b/webkit/glue/plugins/webplugin_delegate_impl_gtk.cc
index 3d112fa..bceda0e 100644
--- a/webkit/glue/plugins/webplugin_delegate_impl_gtk.cc
+++ b/webkit/glue/plugins/webplugin_delegate_impl_gtk.cc
@@ -14,7 +14,7 @@
 #include "base/file_util.h"
 #include "base/message_loop.h"
 #include "base/process_util.h"
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
 #include "base/string_util.h"
 #include "gfx/blit.h"
 #include "skia/ext/platform_canvas.h"
@@ -443,8 +443,8 @@ void WebPluginDelegateImpl::WindowlessPaint(cairo_t* context,
     }
 
     // Tell the plugin to paint into the pixmap.
-    static StatsRate plugin_paint("Plugin.Paint");
-    StatsScope<StatsRate> scope(plugin_paint);
+    static base::StatsRate plugin_paint("Plugin.Paint");
+    base::StatsScope<base::StatsRate> scope(plugin_paint);
     NPError err = instance()->NPP_HandleEvent(&np_event);
     DCHECK_EQ(err, NPERR_NO_ERROR);
 
@@ -474,8 +474,8 @@ void WebPluginDelegateImpl::WindowlessPaint(cairo_t* context,
     event.drawable = GDK_PIXMAP_XID(pixmap_);
 
     // Tell the plugin to paint into the pixmap.
-    static StatsRate plugin_paint("Plugin.Paint");
-    StatsScope<StatsRate> scope(plugin_paint);
+    static base::StatsRate plugin_paint("Plugin.Paint");
+    base::StatsScope<base::StatsRate> scope(plugin_paint);
     NPError err = instance()->NPP_HandleEvent(&np_event);
     DCHECK_EQ(err, NPERR_NO_ERROR);
 
diff --git a/webkit/glue/plugins/webplugin_delegate_impl_mac.mm b/webkit/glue/plugins/webplugin_delegate_impl_mac.mm
index 11d244c..b7e7702 100644
--- a/webkit/glue/plugins/webplugin_delegate_impl_mac.mm
+++ b/webkit/glue/plugins/webplugin_delegate_impl_mac.mm
@@ -13,8 +13,8 @@
 
 #include "base/file_util.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_counters.h"
 #include "base/scoped_ptr.h"
-#include "base/stats_counters.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebInputEvent.h"
@@ -650,8 +650,8 @@ void WebPluginDelegateImpl::WindowlessPaint(gfx::NativeDrawingContext context,
     return;
   DCHECK(buffer_context_ == context);
 
-  static StatsRate plugin_paint("Plugin.Paint");
-  StatsScope<StatsRate> scope(plugin_paint);
+  static base::StatsRate plugin_paint("Plugin.Paint");
+  base::StatsScope<base::StatsRate> scope(plugin_paint);
 
   // Plugin invalidates trigger asynchronous paints with the original
   // invalidation rect; the plugin may be resized before the paint is handled,
diff --git a/webkit/glue/plugins/webplugin_delegate_impl_win.cc b/webkit/glue/plugins/webplugin_delegate_impl_win.cc
index 2a10775..c9500d1 100644
--- a/webkit/glue/plugins/webplugin_delegate_impl_win.cc
+++ b/webkit/glue/plugins/webplugin_delegate_impl_win.cc
@@ -12,9 +12,9 @@
 #include "base/iat_patch.h"
 #include "base/lazy_instance.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_counters.h"
 #include "base/registry.h"
 #include "base/scoped_ptr.h"
-#include "base/stats_counters.h"
 #include "base/string_number_conversions.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
@@ -1029,8 +1029,8 @@ void WebPluginDelegateImpl::WindowlessPaint(HDC hdc,
   // NOTE: NPAPI is not 64bit safe.  It puts pointers into 32bit values.
   paint_event.wParam = PtrToUlong(hdc);
   paint_event.lParam = PtrToUlong(&damage_rect_win);
-  static StatsRate plugin_paint("Plugin.Paint");
-  StatsScope<StatsRate> scope(plugin_paint);
+  static base::StatsRate plugin_paint("Plugin.Paint");
+  base::StatsScope<base::StatsRate> scope(plugin_paint);
   instance()->NPP_HandleEvent(&paint_event);
   window_.window = old_dc;
 }
diff --git a/webkit/glue/plugins/webview_plugin.cc b/webkit/glue/plugins/webview_plugin.cc
index 9287028..feb5720 100644
--- a/webkit/glue/plugins/webview_plugin.cc
+++ b/webkit/glue/plugins/webview_plugin.cc
@@ -4,8 +4,8 @@
 
 #include "webkit/glue/plugins/webview_plugin.h"
 
-#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebCursorInfo.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebPluginContainer.h"
diff --git a/webkit/glue/site_isolation_metrics.cc b/webkit/glue/site_isolation_metrics.cc
index 912263f..58d8717 100644
--- a/webkit/glue/site_isolation_metrics.cc
+++ b/webkit/glue/site_isolation_metrics.cc
@@ -7,7 +7,7 @@
 #include <set>
 
 #include "base/hash_tables.h"
-#include "base/histogram.h"
+#include "base/metrics/histogram.h"
 #include "net/base/mime_sniffer.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebSecurityOrigin.h"
diff --git a/webkit/glue/webkitclient_impl.cc b/webkit/glue/webkitclient_impl.cc
index e9b05f1..648f3bd5 100644
--- a/webkit/glue/webkitclient_impl.cc
+++ b/webkit/glue/webkitclient_impl.cc
@@ -14,10 +14,10 @@
 
 #include "base/lock.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_counters.h"
 #include "base/process_util.h"
 #include "base/platform_file.h"
 #include "base/singleton.h"
-#include "base/stats_counters.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/time.h"
@@ -217,11 +217,11 @@ void WebKitClientImpl::getPluginList(bool refresh,
 }
 
 void WebKitClientImpl::decrementStatsCounter(const char* name) {
-  StatsCounter(name).Decrement();
+  base::StatsCounter(name).Decrement();
 }
 
 void WebKitClientImpl::incrementStatsCounter(const char* name) {
-  StatsCounter(name).Increment();
+  base::StatsCounter(name).Increment();
 }
 
 void WebKitClientImpl::traceEventBegin(const char* name, void* id,
diff --git a/webkit/support/test_webkit_client.cc b/webkit/support/test_webkit_client.cc
index 2bc1494..3bceef0 100644
--- a/webkit/support/test_webkit_client.cc
+++ b/webkit/support/test_webkit_client.cc
@@ -2,10 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "webkit/support/test_webkit_client.h"
+
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "base/scoped_temp_dir.h"
-#include "base/stats_counters.h"
+#include "base/metrics/stats_counters.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "net/base/cookie_monster.h"
@@ -37,7 +39,6 @@
 #include "webkit/glue/webclipboard_impl.h"
 #include "webkit/glue/webkit_glue.h"
 #include "webkit/glue/webkitclient_impl.h"
-#include "webkit/support/test_webkit_client.h"
 #include "webkit/support/weburl_loader_mock_factory.h"
 #include "webkit/tools/test_shell/mock_webclipboard_impl.h"
 #include "webkit/tools/test_shell/simple_appcache_system.h"
@@ -62,7 +63,7 @@ using WebKit::WebScriptController;
 
 TestWebKitClient::TestWebKitClient(bool unit_test_mode)
       : unit_test_mode_(unit_test_mode) {
-  v8::V8::SetCounterFunction(StatsTable::FindLocation);
+  v8::V8::SetCounterFunction(base::StatsTable::FindLocation);
 
   WebKit::initialize(this);
   WebKit::setLayoutTestMode(true);
diff --git a/webkit/tools/test_shell/test_shell.cc b/webkit/tools/test_shell/test_shell.cc
index 9213f6b..64af309 100644
--- a/webkit/tools/test_shell/test_shell.cc
+++ b/webkit/tools/test_shell/test_shell.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -16,8 +16,8 @@
 #endif
 #include "base/md5.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_table.h"
 #include "base/path_service.h"
-#include "base/stats_table.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "build/build_config.h"
@@ -178,7 +178,7 @@ TestShell::~TestShell() {
 
   PlatformCleanUp();
 
-  StatsTable *table = StatsTable::current();
+  base::StatsTable *table = base::StatsTable::current();
   if (dump_stats_table_on_exit_) {
     // Dump the stats table.
     printf("<stats>\n");
diff --git a/webkit/tools/test_shell/test_shell_mac.mm b/webkit/tools/test_shell/test_shell_mac.mm
index ca49b66..f34dd21 100644
--- a/webkit/tools/test_shell/test_shell_mac.mm
+++ b/webkit/tools/test_shell/test_shell_mac.mm
@@ -19,7 +19,6 @@
 #include "base/memory_debug.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
-#include "base/stats_table.h"
 #include "base/string16.h"
 #include "base/string_piece.h"
 #include "base/utf_string_conversions.h"
diff --git a/webkit/tools/test_shell/test_shell_main.cc b/webkit/tools/test_shell/test_shell_main.cc
index 12b3b1c..a41ce74 100644
--- a/webkit/tools/test_shell/test_shell_main.cc
+++ b/webkit/tools/test_shell/test_shell_main.cc
@@ -14,10 +14,10 @@
 #include "base/i18n/icu_util.h"
 #include "base/memory_debug.h"
 #include "base/message_loop.h"
+#include "base/metrics/stats_table.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/rand_util.h"
-#include "base/stats_table.h"
 #include "base/string_number_conversions.h"
 #include "base/sys_info.h"
 #include "base/trace_event.h"
@@ -273,10 +273,10 @@ int main(int argc, char* argv[]) {
   std::string stats_filename = kStatsFilePrefix +
       base::Uint64ToString(base::RandUint64() & 0xFFFFFFFFL);
   RemoveSharedMemoryFile(stats_filename);
-  StatsTable *table = new StatsTable(stats_filename,
+  base::StatsTable *table = new base::StatsTable(stats_filename,
       kStatsFileThreads,
       kStatsFileCounters);
-  StatsTable::set_current(table);
+  base::StatsTable::set_current(table);
 
   TestShell* shell;
   if (TestShell::CreateNewWindow(starting_url, &shell)) {
@@ -398,7 +398,7 @@ int main(int argc, char* argv[]) {
   TestShell::CleanupLogging();
 
   // Tear down shared StatsTable; prevents unit_tests from leaking it.
-  StatsTable::set_current(NULL);
+  base::StatsTable::set_current(NULL);
   delete table;
   RemoveSharedMemoryFile(stats_filename);
 
diff --git a/webkit/tools/test_shell/test_shell_webkit_init.cc b/webkit/tools/test_shell/test_shell_webkit_init.cc
index 812d815..afae8f2 100644
--- a/webkit/tools/test_shell/test_shell_webkit_init.cc
+++ b/webkit/tools/test_shell/test_shell_webkit_init.cc
@@ -4,8 +4,8 @@
 
 #include "webkit/tools/test_shell/test_shell_webkit_init.h"
 
+#include "base/metrics/stats_counters.h"
 #include "base/path_service.h"
-#include "base/stats_counters.h"
 #include "media/base/media.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebDatabase.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebKit.h"
@@ -20,7 +20,7 @@
 #endif
 
 TestShellWebKitInit::TestShellWebKitInit(bool layout_test_mode) {
-  v8::V8::SetCounterFunction(StatsTable::FindLocation);
+  v8::V8::SetCounterFunction(base::StatsTable::FindLocation);
 
   WebKit::initialize(this);
   WebKit::setLayoutTestMode(layout_test_mode);