Enable FCM on mac and threaded-compositing on Windows on Canary/Dev

chrome/browser/chrome_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/chrome_gpu_util.h"
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/version.h"
@@ skipping 136 matching lines @@
   // field trial.
   if (!ShouldRunCompositingFieldTrial()) {
     DisableCompositingFieldTrial();
     return;
   }
 
   const base::FieldTrial::Probability kDivisor = 3;
   scoped_refptr<base::FieldTrial> trial(
     base::FieldTrialList::FactoryGetFieldTrial(
         content::kGpuCompositingFieldTrialName, kDivisor,
-        "disable", 2012, 12, 31, NULL));
+        "disable", 2013, 12, 31, NULL));
 
   // Produce the same result on every run of this client.
   trial->UseOneTimeRandomization();
 
   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
+
   chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
-  if (channel == chrome::VersionInfo::CHANNEL_STABLE ||
-      channel == chrome::VersionInfo::CHANNEL_BETA) {
-    // Stable and Beta channels: Non-threaded force-compositing-mode on by
-    // default (mac and windows only).
-#if defined(OS_WIN) || defined(OS_MACOSX)
-    force_compositing_mode_probability = 3;
-#endif
-  } else if (channel == chrome::VersionInfo::CHANNEL_DEV ||
-             channel == chrome::VersionInfo::CHANNEL_CANARY) {
-    // Dev and Canary channels: force-compositing-mode and
-    // threaded-compositing on with 1/3 probability each.
-    force_compositing_mode_probability = 1;
-
-#if defined(OS_MACOSX) || defined(OS_LINUX)
-    // Threaded compositing mode isn't feature complete on mac or linux yet:
-    // http://crbug.com/133602 for mac
-    // http://crbug.com/140866 for linux
-    threaded_compositing_probability = 0;
-#else
-    if (!CommandLine::ForCurrentProcess()->HasSwitch(
-            switches::kDisableThreadedCompositing))
-        threaded_compositing_probability = 1;
+  if (channel == chrome::VersionInfo::CHANNEL_CANARY ||
+      channel == chrome::VersionInfo::CHANNEL_DEV) {
+#if defined(OS_WIN)
+    // Enable threaded compositing on Windows.
+    threaded_compositing_probability = kDivisor;
+#elif defined(OS_MACOSX)
+    // Enable force-compositing-mode on the Mac.
+    force_compositing_mode_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;