Always enable FCM on Windows.

content/browser/gpu/compositor_util.cc

Index: content/browser/gpu/compositor_util.cc
diff --git a/content/browser/gpu/compositor_util.cc b/content/browser/gpu/compositor_util.cc
index 96c626427f528d476805bf3c9090d7512ef8df5c..1c3ff04ac6887263b939c7ab6f70477c5dae5e1e 100644
--- a/content/browser/gpu/compositor_util.cc
+++ b/content/browser/gpu/compositor_util.cc
@@ -6,6 +6,7 @@
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
+#include "build/build_config.h"
 #include "content/public/browser/gpu_data_manager.h"
 #include "content/public/common/content_constants.h"
 #include "content/public/common/content_switches.h"
@@ -36,11 +37,6 @@ bool CanDoAcceleratedCompositing() {
   return true;
 }
 
-bool IsForceCompositingModeBlacklisted() {
-  return GpuDataManager::GetInstance()->IsFeatureBlacklisted(
-      gpu::GPU_FEATURE_TYPE_FORCE_COMPOSITING_MODE);
-}
-
 }  // namespace
 
 bool IsThreadedCompositingEnabled() {
@@ -49,9 +45,6 @@ bool IsThreadedCompositingEnabled() {
   return true;
 #endif
 
-  if (!CanDoAcceleratedCompositing())
-    return false;
-
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
   // Command line switches take precedence over blacklist and field trials.
@@ -68,7 +61,7 @@ bool IsThreadedCompositingEnabled() {
   if (command_line.HasSwitch(switches::kEnableThreadedCompositing))
     return true;
 
-  if (IsForceCompositingModeBlacklisted())
+  if (!CanDoAcceleratedCompositing())
     return false;
 
   base::FieldTrial* trial =
@@ -78,14 +71,11 @@ bool IsThreadedCompositingEnabled() {
 }
 
 bool IsForceCompositingModeEnabled() {
-#if defined(OS_WIN)
+#if defined(OS_WIN) && defined(USE_AURA)
   // We always want compositing on Aura Windows.
   return true;
 #endif
 
-  if (!CanDoAcceleratedCompositing())
-    return false;
-
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
   // Command line switches take precedence over blacklisting and field trials.
@@ -100,9 +90,18 @@ bool IsForceCompositingModeEnabled() {
   if (command_line.HasSwitch(switches::kForceCompositingMode))
     return true;
 
-  if (IsForceCompositingModeBlacklisted())
+  if (!CanDoAcceleratedCompositing())
     return false;
 
+#if defined(OS_WIN)
+  // Windows Vista+ has been shipping with FCM enabled at 100% since M24; skip
+  // the field trial check to ensure this is always enabled on the try bots.
+  // TODO(gab): Do the same thing in IsThreadedCompositingEnabled() once this is
+  // stable.
+  // TODO(gab): Do the same thing for Mac OS (which has been enabled at 100%

[wiltzius, 2013/08/06 16:58:14]

Be careful about the Mac code, since it's only enabled for 10.8 (not 10.6 and
10.7). ccameron@ is weighing the possibility of backporting to 10.6 and 10.7
now; so good to coordinate with him (or let him clean this up)

+  // since M28) as well and get rid of the field trial code.
+  return true;
+#else
   base::FieldTrial* trial =
       base::FieldTrialList::Find(kGpuCompositingFieldTrialName);
 
@@ -112,6 +111,7 @@ bool IsForceCompositingModeEnabled() {
         (trial->group_name() ==
             kGpuCompositingFieldTrialForceCompositingEnabledName ||
          trial->group_name() == kGpuCompositingFieldTrialThreadEnabledName);
+#endif
 }
 
 }  // namespace content