Move //components/metrics/compression_utils into standalone component

This file is used by code in //chrome/browser/metrics/variations that itself is
slated for componentization. As //components/metrics depends on
//components/variations, the code in question would not be able to be
componentized into //components/variations. To enable that, this CL moves
compression_utils* to a standalone lower-level component.

BUG=516662, 515695
TBR=agl

Review URL: https://codereview.chromium.org/1304563003

Cr-Commit-Position: refs/heads/master@{#345309}

23 files changed, 102 insertions, 37 deletions

diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 10202ed..9b7771a 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -108,6 +108,7 @@ source_set("browser") {
     "//components/captive_portal",
     "//components/cloud_devices/common",
     "//components/component_updater",
+    "//components/compression",
     "//components/content_settings/content/common",
     "//components/content_settings/core/browser",
     "//components/content_settings/core/common",
diff --git a/chrome/browser/DEPS b/chrome/browser/DEPS
index 640f9b9..753c683 100644
--- a/chrome/browser/DEPS
+++ b/chrome/browser/DEPS
@@ -26,6 +26,7 @@ include_rules = [
   "+components/cdm/browser",
   "+components/cloud_devices/common",
   "+components/component_updater",
+  "+components/compression",
   "+components/content_settings",
   "+components/copresence",
   "+components/crash",
diff --git a/chrome/browser/metrics/variations/variations_seed_store.cc b/chrome/browser/metrics/variations/variations_seed_store.cc
index 3eb15a8..209cd88 100644
--- a/chrome/browser/metrics/variations/variations_seed_store.cc
+++ b/chrome/browser/metrics/variations/variations_seed_store.cc
@@ -11,7 +11,7 @@
 #include "base/prefs/pref_service.h"
 #include "base/sha1.h"
 #include "base/strings/string_number_conversions.h"
-#include "components/metrics/compression_utils.h"
+#include "components/compression/compression_utils.h"
 #include "components/variations/pref_names.h"
 #include "components/variations/proto/variations_seed.pb.h"
 #include "crypto/signature_verifier.h"
@@ -331,7 +331,7 @@ bool VariationsSeedStore::ReadSeedData(std::string* seed_data) {
 
   if (!is_compressed) {
     seed_data->swap(decoded_data);
-  } else if (!metrics::GzipUncompress(decoded_data, seed_data)) {
+  } else if (!compression::GzipUncompress(decoded_data, seed_data)) {
     ClearPrefs();
     RecordVariationSeedEmptyHistogram(VARIATIONS_SEED_CORRUPT_GZIP);
     return false;
@@ -371,7 +371,7 @@ bool VariationsSeedStore::StoreSeedDataNoDelta(
 
   // Compress the seed before base64-encoding and storing.
   std::string compressed_seed_data;
-  if (!metrics::GzipCompress(seed_data, &compressed_seed_data)) {
+  if (!compression::GzipCompress(seed_data, &compressed_seed_data)) {
     RecordSeedStoreHistogram(VARIATIONS_SEED_STORE_FAILED_GZIP);
     return false;
   }
diff --git a/chrome/browser/metrics/variations/variations_seed_store_unittest.cc b/chrome/browser/metrics/variations/variations_seed_store_unittest.cc
index 7e3c6c7..50a7546 100644
--- a/chrome/browser/metrics/variations/variations_seed_store_unittest.cc
+++ b/chrome/browser/metrics/variations/variations_seed_store_unittest.cc
@@ -6,7 +6,7 @@
 
 #include "base/base64.h"
 #include "base/prefs/testing_pref_service.h"
-#include "components/metrics/compression_utils.h"
+#include "components/compression/compression_utils.h"
 #include "components/variations/pref_names.h"
 #include "components/variations/proto/study.pb.h"
 #include "components/variations/proto/variations_seed.pb.h"
@@ -64,7 +64,7 @@ std::string SerializeSeed(const variations::VariationsSeed& seed) {
 // Compresses |data| using Gzip compression and returns the result.
 std::string Compress(const std::string& data) {
   std::string compressed;
-  const bool result = metrics::GzipCompress(data, &compressed);
+  const bool result = compression::GzipCompress(data, &compressed);
   EXPECT_TRUE(result);
   return compressed;
 }
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index ef36c8c..338011c 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -3117,6 +3117,7 @@
         '../components/components.gyp:cloud_devices_common',
         '../components/components.gyp:component_metrics_proto',
         '../components/components.gyp:component_updater',
+        '../components/components.gyp:compression',
         '../components/components.gyp:content_settings_content_common',
         '../components/components.gyp:content_settings_core_browser',
         '../components/components.gyp:content_settings_core_common',
diff --git a/components/BUILD.gn b/components/BUILD.gn
index 7d2729b..9478c17 100644
--- a/components/BUILD.gn
+++ b/components/BUILD.gn
@@ -30,6 +30,7 @@ group("all_components") {
     "//components/cloud_devices/common",
     "//components/chrome_apps",
     "//components/component_updater",
+    "//components/compression",
     "//components/content_settings/core/browser",
     "//components/content_settings/core/common",
     "//components/crash/app",
diff --git a/components/components.gyp b/components/components.gyp
index 9990cbf..e8012d5 100644
--- a/components/components.gyp
+++ b/components/components.gyp
@@ -17,6 +17,7 @@
     'captive_portal.gypi',
     'cloud_devices.gypi',
     'component_updater.gypi',
+    'compression.gypi',
     'content_settings.gypi',
     'crash.gypi',
     'crash_keys.gypi',
diff --git a/components/components_tests.gyp b/components/components_tests.gyp
index 70cbb79..d19f2cc 100644
--- a/components/components_tests.gyp
+++ b/components/components_tests.gyp
@@ -11,7 +11,7 @@
 
     # Note: sources list duplicated in GN build. In the GN build,
     # each component has its own unit tests target defined in its
-    # directory that are then linked into the final content_unittests.
+    # directory that are then linked into the final components_unittests.
     'auto_login_parser_unittest_sources': [
       'auto_login_parser/auto_login_parser_unittest.cc',
     ],
@@ -92,6 +92,9 @@
       'component_updater/component_updater_service_unittest.cc',
       'component_updater/timer_unittest.cc',
     ],
+    'compression_unittest_sources': [
+      'compression/compression_utils_unittest.cc',
+    ],
     'content_settings_unittest_sources': [
       'content_settings/core/browser/content_settings_mock_provider.cc',
       'content_settings/core/browser/content_settings_mock_provider.h',
@@ -306,7 +309,6 @@
     ],
     'metrics_unittest_sources': [
       'metrics/call_stack_profile_metrics_provider_unittest.cc',
-      'metrics/compression_utils_unittest.cc',
       'metrics/daily_event_unittest.cc',
       'metrics/drive_metrics_provider_unittest.cc',
       'metrics/gpu/gpu_metrics_provider_unittest.cc',
@@ -750,6 +752,7 @@
         '<@(captive_portal_unittest_sources)',
         '<@(cloud_devices_unittest_sources)',
         '<@(component_updater_unittest_sources)',
+        '<@(compression_unittest_sources)',
         '<@(content_settings_unittest_sources)',
         '<@(crash_unittest_sources)',
         '<@(crx_file_unittest_sources)',
@@ -844,6 +847,7 @@
         'components.gyp:captive_portal_test_support',
         'components.gyp:cloud_devices_common',
         'components.gyp:component_updater',
+        'components.gyp:compression',
         'components.gyp:content_settings_core_browser',
         'components.gyp:content_settings_core_common',
         'components.gyp:content_settings_core_test_support',
diff --git a/components/compression.gypi b/components/compression.gypi
new file mode 100644
index 0000000..4c98971
--- /dev/null
+++ b/components/compression.gypi
@@ -0,0 +1,24 @@
+# Copyright 2015 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.
+
+{
+  'targets': [
+    {
+      # GN version: //components/compression
+      'target_name': 'compression',
+      'type': 'static_library',
+      'include_dirs': [
+        '..',
+      ],
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../third_party/zlib/zlib.gyp:zlib',
+      ],
+      'sources': [
+        'compression/compression_utils.cc',
+        'compression/compression_utils.h',
+      ],
+    },
+  ],
+}
diff --git a/components/compression/BUILD.gn b/components/compression/BUILD.gn
new file mode 100644
index 0000000..e35fe23
--- /dev/null
+++ b/components/compression/BUILD.gn
@@ -0,0 +1,26 @@
+# Copyright 2015 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.
+
+# GYP version: components/compression.gypi:compression
+source_set("compression") {
+  sources = [
+    "compression_utils.cc",
+    "compression_utils.h",
+  ]
+  deps = [
+    "//base",
+    "//third_party/zlib",
+  ]
+}
+
+source_set("unit_tests") {
+  testonly = true
+  sources = [
+    "compression_utils_unittest.cc",
+  ]
+  deps = [
+    ":compression",
+    "//testing/gtest",
+  ]
+}
diff --git a/components/compression/DEPS b/components/compression/DEPS
new file mode 100644
index 0000000..670343e
--- /dev/null
+++ b/components/compression/DEPS
@@ -0,0 +1,3 @@
+include_rules = [ 
+  "+third_party/zlib",
+]
diff --git a/components/compression/OWNERS b/components/compression/OWNERS
new file mode 100644
index 0000000..e17cf14
--- /dev/null
+++ b/components/compression/OWNERS
@@ -0,0 +1,6 @@
+asvitkine@chromium.org
+holte@chromium.org
+isherman@chromium.org
+jar@chromium.org
+mpearson@chromium.org
+rkaplow@chromium.org
diff --git a/components/metrics/compression_utils.cc b/components/compression/compression_utils.cc
index da099ae..19de730 100644
--- a/components/metrics/compression_utils.cc
+++ b/components/compression/compression_utils.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "components/metrics/compression_utils.h"
+#include "components/compression/compression_utils.h"
 
 #include <vector>
 
@@ -123,7 +123,7 @@ uint32 GetUncompressedSize(const std::string& compressed_data) {
 
 }  // namespace
 
-namespace metrics {
+namespace compression {
 
 bool GzipCompress(const std::string& input, std::string* output) {
   const uLongf input_size = static_cast<uLongf>(input.size());
@@ -158,4 +158,4 @@ bool GzipUncompress(const std::string& input, std::string* output) {
   return false;
 }
 
-}  // namespace metrics
+}  // namespace compression
diff --git a/components/metrics/compression_utils.h b/components/compression/compression_utils.h
index 0aa407f..46cfd51 100644
--- a/components/metrics/compression_utils.h
+++ b/components/compression/compression_utils.h
@@ -2,12 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef COMPONENTS_METRICS_COMPRESSION_UTILS_H_
-#define COMPONENTS_METRICS_COMPRESSION_UTILS_H_
+#ifndef COMPONENTS_COMPRESSION_COMPRESSION_UTILS_H_
+#define COMPONENTS_COMPRESSION_COMPRESSION_UTILS_H_
 
 #include <string>
 
-namespace metrics {
+namespace compression {
 
 // Compresses the data in |input| using gzip, storing the result in |output|.
 // |input| and |output| are allowed to be the same string (in-place operation).
@@ -17,6 +17,6 @@ bool GzipCompress(const std::string& input, std::string* output);
 // |input| and |output| are allowed to be the same string (in-place operation).
 bool GzipUncompress(const std::string& input, std::string* output);
 
-}  // namespace metrics
+}  // namespace compression
 
-#endif  // COMPONENTS_METRICS_COMPRESSION_UTILS_H_
+#endif  // COMPONENTS_COMPRESSION_COMPRESSION_UTILS_H_
diff --git a/components/metrics/compression_utils_unittest.cc b/components/compression/compression_utils_unittest.cc
index 722e835..793a706 100644
--- a/components/metrics/compression_utils_unittest.cc
+++ b/components/compression/compression_utils_unittest.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "components/metrics/compression_utils.h"
+#include "components/compression/compression_utils.h"
 
 #include <string>
 
@@ -10,7 +10,7 @@
 #include "base/logging.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-namespace metrics {
+namespace compression {
 
 namespace {
 
@@ -87,4 +87,4 @@ TEST(CompressionUtilsTest, InPlace) {
   EXPECT_EQ(original_data, data);
 }
 
-}  // namespace metrics
+}  // namespace compression
diff --git a/components/metrics.gypi b/components/metrics.gypi
index d6bdbdc..28126bd 100644
--- a/components/metrics.gypi
+++ b/components/metrics.gypi
@@ -15,8 +15,8 @@
         '../base/base.gyp:base',
         '../base/base.gyp:base_i18n',
         '../base/base.gyp:base_prefs',
-        '../third_party/zlib/zlib.gyp:zlib',
         'component_metrics_proto',
+        'compression',
         'variations',
       ],
       'export_dependent_settings': [
@@ -31,8 +31,6 @@
         'metrics/client_info.h',
         'metrics/cloned_install_detector.cc',
         'metrics/cloned_install_detector.h',
-        'metrics/compression_utils.cc',
-        'metrics/compression_utils.h',
         'metrics/daily_event.cc',
         'metrics/daily_event.h',
         'metrics/drive_metrics_provider.cc',
diff --git a/components/metrics/BUILD.gn b/components/metrics/BUILD.gn
index 3a5fd4d..114fc3d 100644
--- a/components/metrics/BUILD.gn
+++ b/components/metrics/BUILD.gn
@@ -13,8 +13,6 @@ source_set("metrics") {
     "client_info.h",
     "cloned_install_detector.cc",
     "cloned_install_detector.h",
-    "compression_utils.cc",
-    "compression_utils.h",
     "daily_event.cc",
     "daily_event.h",
     "drive_metrics_provider.cc",
@@ -66,8 +64,8 @@ source_set("metrics") {
     "//base",
     "//base:i18n",
     "//base:prefs",
+    "//components/compression",
     "//components/variations",
-    "//third_party/zlib",
   ]
 
   if (is_chromeos) {
@@ -178,7 +176,6 @@ source_set("unit_tests") {
   testonly = true
   sources = [
     "call_stack_profile_metrics_provider_unittest.cc",
-    "compression_utils_unittest.cc",
     "daily_event_unittest.cc",
     "drive_metrics_provider_unittest.cc",
     "gpu/gpu_metrics_provider_unittest.cc",
diff --git a/components/metrics/DEPS b/components/metrics/DEPS
index aa5bdc7..2f4d413 100644
--- a/components/metrics/DEPS
+++ b/components/metrics/DEPS
@@ -2,8 +2,8 @@
 # dependencies to a minimal set.
 include_rules = [ 
   "-components",
+  "+components/compression",
   "+components/metrics",
   "+components/variations",
   "-net",
-  "+third_party/zlib",
 ]
diff --git a/components/metrics/metrics_service_unittest.cc b/components/metrics/metrics_service_unittest.cc
index 621e2ba..453e118 100644
--- a/components/metrics/metrics_service_unittest.cc
+++ b/components/metrics/metrics_service_unittest.cc
@@ -12,8 +12,8 @@
 #include "base/metrics/statistics_recorder.h"
 #include "base/prefs/testing_pref_service.h"
 #include "base/threading/platform_thread.h"
+#include "components/compression/compression_utils.h"
 #include "components/metrics/client_info.h"
-#include "components/metrics/compression_utils.h"
 #include "components/metrics/metrics_hashes.h"
 #include "components/metrics/metrics_log.h"
 #include "components/metrics/metrics_pref_names.h"
@@ -229,7 +229,8 @@ TEST_F(MetricsServiceTest, InitialStabilityLogAtProviderRequest) {
   EXPECT_TRUE(log_manager->has_staged_log());
 
   std::string uncompressed_log;
-  EXPECT_TRUE(GzipUncompress(log_manager->staged_log(), &uncompressed_log));
+  EXPECT_TRUE(compression::GzipUncompress(log_manager->staged_log(),
+                                          &uncompressed_log));
 
   ChromeUserMetricsExtension uma_log;
   EXPECT_TRUE(uma_log.ParseFromString(uncompressed_log));
@@ -291,7 +292,8 @@ TEST_F(MetricsServiceTest, InitialStabilityLogAfterCrash) {
   EXPECT_TRUE(log_manager->has_staged_log());
 
   std::string uncompressed_log;
-  EXPECT_TRUE(GzipUncompress(log_manager->staged_log(), &uncompressed_log));
+  EXPECT_TRUE(compression::GzipUncompress(log_manager->staged_log(),
+                                          &uncompressed_log));
 
   ChromeUserMetricsExtension uma_log;
   EXPECT_TRUE(uma_log.ParseFromString(uncompressed_log));
diff --git a/components/metrics/persisted_logs.cc b/components/metrics/persisted_logs.cc
index ef562d6..e28ae4a 100644
--- a/components/metrics/persisted_logs.cc
+++ b/components/metrics/persisted_logs.cc
@@ -13,7 +13,7 @@
 #include "base/prefs/scoped_user_pref_update.h"
 #include "base/sha1.h"
 #include "base/timer/elapsed_timer.h"
-#include "components/metrics/compression_utils.h"
+#include "components/compression/compression_utils.h"
 
 namespace metrics {
 
@@ -49,7 +49,7 @@ void AppendBase64String(const std::string& str, base::ListValue* list_value) {
 void PersistedLogs::LogHashPair::Init(const std::string& log_data) {
   DCHECK(!log_data.empty());
 
-  if (!GzipCompress(log_data, &compressed_log_data)) {
+  if (!compression::GzipCompress(log_data, &compressed_log_data)) {
     NOTREACHED();
     return;
   }
diff --git a/components/metrics/persisted_logs_unittest.cc b/components/metrics/persisted_logs_unittest.cc
index c9153de..09b84af 100644
--- a/components/metrics/persisted_logs_unittest.cc
+++ b/components/metrics/persisted_logs_unittest.cc
@@ -11,7 +11,7 @@
 #include "base/rand_util.h"
 #include "base/sha1.h"
 #include "base/values.h"
-#include "components/metrics/compression_utils.h"
+#include "components/compression/compression_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace metrics {
@@ -25,7 +25,7 @@ const size_t kLogByteLimit = 1000;
 // Compresses |log_data| and returns the result.
 std::string Compress(const std::string& log_data) {
   std::string compressed_log_data;
-  EXPECT_TRUE(GzipCompress(log_data, &compressed_log_data));
+  EXPECT_TRUE(compression::GzipCompress(log_data, &compressed_log_data));
   return compressed_log_data;
 }
 
diff --git a/sync/internal_api/http_bridge.cc b/sync/internal_api/http_bridge.cc
index e5729f2..04e339c 100644
--- a/sync/internal_api/http_bridge.cc
+++ b/sync/internal_api/http_bridge.cc
@@ -62,9 +62,9 @@ void RecordSyncResponseContentLengthHistograms(int64 compressed_content_length,
 
 // -----------------------------------------------------------------------------
 // The rest of the code in the anon namespace is copied from
-// components/metrics/compression_utils.cc
+// components/compression/compression_utils.cc
 // TODO(gangwu): crbug.com/515695. The following code is copied from
-// components/metrics/compression_utils.cc. We copied them because if we
+// components/compression/compression_utils.cc. We copied them because if we
 // reference them, we will get cycle dependency warning. Once the functions
 // have been moved from //component to //base, we can remove the following
 // functions.
diff --git a/sync/internal_api/http_bridge_unittest.cc b/sync/internal_api/http_bridge_unittest.cc
index 24fc6cd..4ea4e70 100644
--- a/sync/internal_api/http_bridge_unittest.cc
+++ b/sync/internal_api/http_bridge_unittest.cc
@@ -27,9 +27,9 @@ const base::FilePath::CharType kDocRoot[] =
 
 // -----------------------------------------------------------------------------
 // The rest of the code in the anon namespace is copied from
-// components/metrics/compression_utils.cc
+// components/compression/compression_utils.cc
 // TODO(gangwu): crbug.com/515695. The following codes are copied from
-// components/metrics/compression_utils.cc, we copied them because if we
+// components/compression/compression_utils.cc, we copied them because if we
 // reference them, we will get cycle dependency warning. Once the functions
 // have been moved from //component to //base, we can remove the following
 // functions.