Add threaded compositing mode to field trial

chrome/browser/gpu_util.cc

 // 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_util.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/sys_info.h"
 #include "base/values.h"
 #include "base/version.h"
 #include "chrome/browser/gpu_blacklist.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"
 #include "content/public/common/gpu_info.h"
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #elif defined(OS_MACOSX)
 #include "base/mac/mac_util.h"
 #endif
 
 using content::GpuDataManager;
@@ skipping 128 matching lines @@
       entry_index++;
       break;
     case kGpuFeatureDisabled:
       entry_index += 2;
       break;
   }
   return entry_index;
 }
 #endif  // OS_WIN
 
+bool InForceThreadedCompositingModeTrial() {
+  base::FieldTrial* trial =
+      base::FieldTrialList::Find(content::kGpuCompositingFieldTrialName);
+  return trial && trial->group_name() ==
+      content::kGpuCompositingFieldTrialThreadEnabledName;
+}
+
 }  // namespace
 
 namespace gpu_util {
 
-const char kForceCompositingModeFieldTrialName[] = "ForceCompositingMode";
-const char kFieldTrialEnabledName[] = "enabled";
-
 void InitializeForceCompositingModeFieldTrial() {
 // Enable the field trial only on desktop OS's.
 #if !(defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX))
   return;
 #endif
   chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
   // Only run the trial on the Canary and Dev channels.
   if (channel != chrome::VersionInfo::CHANNEL_CANARY &&
       channel != chrome::VersionInfo::CHANNEL_DEV)
     return;
 #if defined(OS_WIN)
   // Don't run the trial on Windows XP.
   if (base::win::GetVersion() < base::win::VERSION_VISTA)
     return;
 #elif defined(OS_MACOSX)
   // Accelerated compositing is only implemented on Mac OSX 10.6 or later.
   if (base::mac::IsOSLeopardOrEarlier())
     return;
 #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))
+          switches::kDisableForceCompositingMode) ||
+      CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableThreadedCompositing))
     return;
 
-  const base::FieldTrial::Probability kDivisor = 100;
+  const base::FieldTrial::Probability kDivisor = 99;

[Ilya Sherman, 2012/07/20 05:36:05]

Optional nit: Perhaps set this to 3 rather than to 99?  I think 1/3 is clearer
than 33/99, since it's not a percentage either way.

[jbates, 2012/07/23 17:47:00]

Done.

   scoped_refptr<base::FieldTrial> trial(
     base::FieldTrialList::FactoryGetFieldTrial(
-        kForceCompositingModeFieldTrialName, kDivisor,
+        content::kGpuCompositingFieldTrialName, kDivisor,
         "disable", 2012, 12, 31, NULL));
 
   // Produce the same result on every run of this client.
   trial->UseOneTimeRandomization();
-  // 50% probability of being in the enabled group.
-  const base::FieldTrial::Probability kEnableProbability = 50;
+  // (33/99)% probability of being in the enabled or thread group.
+  const base::FieldTrial::Probability kEnableProbability = 33;
   int enable_group = trial->AppendGroup(
-      kFieldTrialEnabledName, kEnableProbability);
+      content::kGpuCompositingFieldTrialEnabledName, kEnableProbability);
+  int thread_group = trial->AppendGroup(
+      content::kGpuCompositingFieldTrialThreadEnabledName, kEnableProbability);
 
   bool enabled = (trial->group() == enable_group);
+  bool thread = (trial->group() == thread_group);
   UMA_HISTOGRAM_BOOLEAN("GPU.InForceCompositingModeFieldTrial", enabled);
+  UMA_HISTOGRAM_BOOLEAN("GPU.InCompositorThreadFieldTrial", thread);
 }
 
-bool InForceCompositingModeTrial() {
+bool InForceCompositingModeOrThreadTrial() {
   base::FieldTrial* trial =
-      base::FieldTrialList::Find(kForceCompositingModeFieldTrialName);
+      base::FieldTrialList::Find(content::kGpuCompositingFieldTrialName);
   if (!trial)
     return false;
-  return trial->group_name() == kFieldTrialEnabledName;
+  return trial->group_name() == content::kGpuCompositingFieldTrialEnabledName ||
+         trial->group_name() ==
+             content::kGpuCompositingFieldTrialThreadEnabledName;
 }
 
 GpuFeatureType StringToGpuFeatureType(const std::string& feature_string) {
   if (feature_string == kGpuFeatureNameAccelerated2dCanvas)
     return content::GPU_FEATURE_TYPE_ACCELERATED_2D_CANVAS;
   else if (feature_string == kGpuFeatureNameAcceleratedCompositing)
     return content::GPU_FEATURE_TYPE_ACCELERATED_COMPOSITING;
   else if (feature_string == kGpuFeatureNameWebgl)
     return content::GPU_FEATURE_TYPE_WEBGL;
   else if (feature_string == kGpuFeatureNameMultisampling)
@@ skipping 130 matching lines @@
           status += "_software";
         else
           status += "_off";
       } else {
         status = "enabled";
         if (kGpuFeatureInfo[i].name == "webgl" &&
             (command_line.HasSwitch(switches::kDisableAcceleratedCompositing) ||
              (flags & content::GPU_FEATURE_TYPE_ACCELERATED_COMPOSITING)))
           status += "_readback";
         bool has_thread =
-            command_line.HasSwitch(switches::kEnableThreadedCompositing) &&
-            !command_line.HasSwitch(switches::kDisableThreadedCompositing);
+            (command_line.HasSwitch(switches::kEnableThreadedCompositing) &&
+             !command_line.HasSwitch(switches::kDisableThreadedCompositing)) ||
+            InForceThreadedCompositingModeTrial();
         if (kGpuFeatureInfo[i].name == "compositing") {
           bool force_compositing =
               (command_line.HasSwitch(switches::kForceCompositingMode) &&
                !command_line.HasSwitch(
                    switches::kDisableForceCompositingMode)) ||
-              InForceCompositingModeTrial();
+              InForceCompositingModeOrThreadTrial();
           if (force_compositing)
             status += "_force";
           if (has_thread)
             status += "_threaded";
         }
         if (kGpuFeatureInfo[i].name == "css_animation") {
           if (has_thread)
             status = "accelerated_threaded";
           else
             status = "accelerated";
@@ skipping 181 matching lines @@
         kGpuBlacklistFeatureHistogramNamesWin[i],
         1, kNumWinSubVersions * kGpuFeatureNumStatus,
         kNumWinSubVersions * kGpuFeatureNumStatus + 1,
         base::Histogram::kUmaTargetedHistogramFlag);
     histogram_pointer->Add(GetGpuBlacklistHistogramValueWin(value));
 #endif
   }
 }
 
 }  // namespace gpu_util;