Use lock-free lazy initialization for static histogram references

Make all histogram macros thread safe, and fast by again
using statics to achieve performance.

...at the cost of:
Leak all histograms to avoid races at shutdown.

Also included leak suppression for valgrind.

r=rtenneti
BUG=78207
Review URL: http://codereview.chromium.org/6780035

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@80412 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 9 insertions, 11 deletions

diff --git a/chrome/browser/chromeos/boot_times_loader.cc b/chrome/browser/chromeos/boot_times_loader.cc
index 4e08290..03359cf 100644
--- a/chrome/browser/chromeos/boot_times_loader.cc
+++ b/chrome/browser/chromeos/boot_times_loader.cc
@@ -259,7 +259,7 @@ void BootTimesLoader::WriteTimes(
   base::Time first = login_times.front().time();
   base::Time last = login_times.back().time();
   base::TimeDelta total = last - first;
-  scoped_refptr<base::Histogram>total_hist = base::Histogram::FactoryTimeGet(
+  base::Histogram* total_hist = base::Histogram::FactoryTimeGet(
       uma_name,
       base::TimeDelta::FromMilliseconds(kMinTimeMillis),
       base::TimeDelta::FromMilliseconds(kMaxTimeMillis),
@@ -277,7 +277,7 @@ void BootTimesLoader::WriteTimes(
 
     if (tm.send_to_uma()) {
       name = uma_prefix + tm.name();
-      scoped_refptr<base::Histogram>prev_hist = base::Histogram::FactoryTimeGet(
+      base::Histogram* prev_hist = base::Histogram::FactoryTimeGet(
           name,
           base::TimeDelta::FromMilliseconds(kMinTimeMillis),
           base::TimeDelta::FromMilliseconds(kMaxTimeMillis),
diff --git a/chrome/browser/chromeos/cros/cros_library_loader.cc b/chrome/browser/chromeos/cros/cros_library_loader.cc
index d631a6c..660bc2c 100644
--- a/chrome/browser/chromeos/cros/cros_library_loader.cc
+++ b/chrome/browser/chromeos/cros/cros_library_loader.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
@@ -22,16 +22,14 @@ void addLibcrosTimeHistogram(const char* name, const base::TimeDelta& delta) {
   static const base::TimeDelta max_time = base::TimeDelta::FromSeconds(1);
   const size_t bucket_count(10);
   DCHECK(name);
-  scoped_refptr<base::Histogram> counter = base::Histogram::FactoryTimeGet(
+  base::Histogram* counter = base::Histogram::FactoryTimeGet(
       std::string(name),
       min_time,
       max_time,
       bucket_count,
       base::Histogram::kNoFlags);
-  if (counter.get()) {
-    counter->AddTime(delta);
-    VLOG(1) << "Cros Time: " << name << ": " << delta.InMilliseconds() << "ms.";
-  }
+  counter->AddTime(delta);
+  VLOG(1) << "Cros Time: " << name << ": " << delta.InMilliseconds() << "ms.";
 }
 
 }  // namespace
diff --git a/chrome/browser/chromeos/external_metrics.cc b/chrome/browser/chromeos/external_metrics.cc
index edd48c0..830de18 100644
--- a/chrome/browser/chromeos/external_metrics.cc
+++ b/chrome/browser/chromeos/external_metrics.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
@@ -86,7 +86,7 @@ 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<base::Histogram> counter = base::Histogram::FactoryGet(
+  base::Histogram* counter = base::Histogram::FactoryGet(
       name, min, max, nbuckets, base::Histogram::kUmaTargetedHistogramFlag);
   counter->Add(sample);
 }
@@ -101,7 +101,7 @@ 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<base::Histogram> counter = base::LinearHistogram::FactoryGet(
+  base::Histogram* counter = base::LinearHistogram::FactoryGet(
       name, 1, max, max + 1, base::Histogram::kUmaTargetedHistogramFlag);
   counter->Add(sample);
 }