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

chrome/browser/chrome_gpu_util.cc

Index: chrome/browser/chrome_gpu_util.cc
diff --git a/chrome/browser/chrome_gpu_util.cc b/chrome/browser/chrome_gpu_util.cc
index c3b1434278eb413bd61541fd89468982603c467b..7885aed3bdba02d5639ac52d775d34922e07fba9 100644
--- a/chrome/browser/chrome_gpu_util.cc
+++ b/chrome/browser/chrome_gpu_util.cc
@@ -154,7 +154,7 @@ void InitializeCompositingFieldTrial() {
   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();
@@ -162,29 +162,19 @@ void InitializeCompositingFieldTrial() {
   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
   }