5 files changed, 133 insertions, 0 deletions
diff --git a/chrome/browser/chrome_browser_field_trials_desktop.cc b/chrome/browser/chrome_browser_field_trials_desktop.cc
index e76120b..c723802 100644
--- a/chrome/browser/chrome_browser_field_trials_desktop.cc
+++ b/chrome/browser/chrome_browser_field_trials_desktop.cc
@@ -14,6 +14,7 @@
 #include "chrome/browser/apps/app_launcher_util.h"
 #include "chrome/browser/auto_launch_trial.h"
 #include "chrome/browser/google/google_util.h"
+#include "chrome/browser/gpu/chrome_gpu_util.h"
 #include "chrome/browser/omnibox/omnibox_field_trial.h"
 #include "chrome/browser/prerender/prerender_field_trial.h"
 #include "chrome/browser/profiles/profiles_state.h"
@@ -129,6 +130,7 @@ void SetupDesktopFieldTrials(const CommandLine& parsed_command_line,
                              PrefService* local_state) {
   prerender::ConfigurePrefetchAndPrerender(parsed_command_line);
   AutoLaunchChromeFieldTrial();
+  gpu_util::InitializeCompositingFieldTrial();
   OmniboxFieldTrial::ActivateStaticTrials();
   SetupInfiniteCacheFieldTrial();
   DisableShowProfileSwitcherTrialIfNecessary();
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index cfd30c3..1319412 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -60,6 +60,7 @@
 #include "chrome/browser/first_run/upgrade_util.h"
 #include "chrome/browser/google/google_search_counter.h"
 #include "chrome/browser/google/google_util.h"
+#include "chrome/browser/gpu/chrome_gpu_util.h"
 #include "chrome/browser/gpu/gl_string_manager.h"
 #include "chrome/browser/jankometer.h"
 #include "chrome/browser/language_usage_metrics.h"
diff --git a/chrome/browser/gpu/chrome_gpu_util.cc b/chrome/browser/gpu/chrome_gpu_util.cc
new file mode 100644
index 0000000..5904713
--- /dev/null
+++ b/chrome/browser/gpu/chrome_gpu_util.cc
@@ -0,0 +1,112 @@
+// Copyright (c) 2012 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/browser/gpu/chrome_gpu_util.h"
+
+#include "base/command_line.h"
+#if defined(OS_MACOSX)
+#include "base/mac/mac_util.h"
+#endif
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
+#include "base/version.h"
+#if defined(OS_WIN)
+#include "base/win/windows_version.h"
+#endif
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list.h"
+#include "chrome/browser/ui/browser_list_observer.h"
+#include "chrome/common/chrome_switches.h"
+#include "chrome/common/chrome_version_info.h"
+#include "content/public/browser/gpu_data_manager.h"
+#include "content/public/common/content_constants.h"
+#include "content/public/common/content_switches.h"
+
+using content::GpuDataManager;
+
+namespace gpu_util {
+
+void DisableCompositingFieldTrial() {
+  base::FieldTrial* trial =
+      base::FieldTrialList::Find(content::kGpuCompositingFieldTrialName);
+  if (trial)
+    trial->Disable();
+}
+
+bool ShouldRunCompositingFieldTrial() {
+// Enable the field trial only on desktop OS's.
+#if !(defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX))
+  return false;
+#endif
+
+// Necessary for linux_chromeos build since it defines both OS_LINUX
+// and OS_CHROMEOS.
+#if defined(OS_CHROMEOS)
+  return false;
+#endif
+
+  // Don't activate the field trial if force-compositing-mode has been
+  // explicitly disabled from the command line.
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableForceCompositingMode) ||
+      CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableAcceleratedCompositing))
+    return false;
+
+  return true;
+}
+
+// Note 1: The compositing field trial may be created at startup time via the
+// Finch framework. In that case, all the Groups and probability values are
+// set before this function is called and any Field Trial setup calls
+// made here are simply ignored.
+// Note 2: Compositing field trials will be overwritten if accelerated
+// compositing is blacklisted. That check takes place in
+// IsThreadedCompositingEnabled() and IsForceCompositingModeEnabled() as
+// the blacklist information isn't available at the time the field trials
+// are initialized.
+// Early outs from this function intended to bypass activation of the field
+// trial must call DisableCompositingFieldTrial() before returning.
+void InitializeCompositingFieldTrial() {
+  // Early out in configurations that should not run the compositing
+  // field trial.
+  if (!ShouldRunCompositingFieldTrial()) {
+    DisableCompositingFieldTrial();
+    return;
+  }
+
+  const base::FieldTrial::Probability kDivisor = 3;
+  scoped_refptr<base::FieldTrial> trial(
+    base::FieldTrialList::FactoryGetFieldTrial(
+        content::kGpuCompositingFieldTrialName, kDivisor,  "disable",
+        2013, 12, 31, base::FieldTrial::ONE_TIME_RANDOMIZED, NULL));
+
+  base::FieldTrial::Probability force_compositing_mode_probability = 0;
+  base::FieldTrial::Probability threaded_compositing_probability = 0;
+
+  // Note: Threaded compositing mode isn't feature complete on mac or linux yet:
+  // http://crbug.com/133602 for mac
+  // http://crbug.com/140866 for linux
+
+#if defined(OS_WIN) || defined(OS_MACOSX)
+  // Enable threaded compositing on Windows and Mac.
+  threaded_compositing_probability = kDivisor;
+#endif
+
+  int force_compositing_group = trial->AppendGroup(
+      content::kGpuCompositingFieldTrialForceCompositingEnabledName,
+      force_compositing_mode_probability);
+  int thread_group = trial->AppendGroup(
+      content::kGpuCompositingFieldTrialThreadEnabledName,
+      threaded_compositing_probability);
+
+  bool force_compositing = (trial->group() == force_compositing_group);
+  bool thread = (trial->group() == thread_group);
+  UMA_HISTOGRAM_BOOLEAN("GPU.InForceCompositingModeFieldTrial",
+                        force_compositing);
+  UMA_HISTOGRAM_BOOLEAN("GPU.InCompositorThreadFieldTrial", thread);
+}
+
+}  // namespace gpu_util
+
diff --git a/chrome/browser/gpu/chrome_gpu_util.h b/chrome/browser/gpu/chrome_gpu_util.h
new file mode 100644
index 0000000..1edff61
--- /dev/null
+++ b/chrome/browser/gpu/chrome_gpu_util.h
@@ -0,0 +1,16 @@
+// Copyright (c) 2012 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 CHROME_BROWSER_GPU_CHROME_GPU_UTIL_H_
+#define CHROME_BROWSER_GPU_CHROME_GPU_UTIL_H_
+
+namespace gpu_util {
+
+// Sets up force-compositing-mode and threaded compositing field trials.
+void InitializeCompositingFieldTrial();
+
+}  // namespace gpu_util
+
+#endif  // CHROME_BROWSER_GPU_CHROME_GPU_UTIL_H_
+
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 334f75e..a1e3bd2 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -703,6 +703,8 @@
         'browser/google_apis/task_util.h',
         'browser/google_apis/time_util.cc',
         'browser/google_apis/time_util.h',
+        'browser/gpu/chrome_gpu_util.cc',
+        'browser/gpu/chrome_gpu_util.h',
         'browser/gpu/gl_string_manager.cc',
         'browser/gpu/gl_string_manager.h',
         'browser/gpu/gpu_feature_checker.cc',