Cleaning up compositing field trial code and enable FCM in beta/stable

content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc

Index: content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
diff --git a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
index 4cf413d69ed01f9fe61e3fcfb29ccc15d87fd324..bb7d4dc1ee72b5d466167f12eda713c53d052e93 100644
--- a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
+++ b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
@@ -151,7 +151,20 @@ WebGraphicsContext3DCommandBufferImpl::WebGraphicsContext3DCommandBufferImpl(
       transfer_buffer_(NULL),
       gl_(NULL),
       frame_number_(0),
-      bind_generates_resources_(false) {
+      bind_generates_resources_(false),
+      use_echo_for_swap_ack_(true) {
+#if defined(OS_MACOSX) || defined(OS_WIN)
+  // Get ViewMsg_SwapBuffers_ACK from browser for single-threaded path.

[darin (slow to review), 2012/08/03 21:16:06]

this is exactly the same logic as in render_view_impl.cc, right?  sounds like
ShouldEnableThreadedCompositing() should be pulled out into a helper function
that lives in content/common/.  threaded_compositor_field_trial.{h,cc}?

+  base::FieldTrial* trial =
+      base::FieldTrialList::Find(content::kGpuCompositingFieldTrialName);
+  bool thread_trial = trial && trial->group_name() ==
+      content::kGpuCompositingFieldTrialThreadEnabledName;
+  use_echo_for_swap_ack_ = thread_trial ||
+      (CommandLine::ForCurrentProcess()->HasSwitch(
+           switches::kEnableThreadedCompositing) &&
+       !CommandLine::ForCurrentProcess()->HasSwitch(
+           switches::kDisableThreadedCompositing));
+#endif
 }
 
 WebGraphicsContext3DCommandBufferImpl::
@@ -521,20 +534,7 @@ void WebGraphicsContext3DCommandBufferImpl::prepareTexture() {
   if (command_buffer_->GetLastState().error == gpu::error::kNoError)
     gl_->SwapBuffers();
 
-  bool use_echo_for_swap_ack = true;
-#if defined(OS_MACOSX) || defined(OS_WIN)
-  // Get ViewMsg_SwapBuffers_ACK from browser for single-threaded path.
-  base::FieldTrial* trial =
-      base::FieldTrialList::Find(content::kGpuCompositingFieldTrialName);
-  bool thread_trial = trial && trial->group_name() ==
-      content::kGpuCompositingFieldTrialThreadEnabledName;
-  use_echo_for_swap_ack = thread_trial ||
-      (CommandLine::ForCurrentProcess()->HasSwitch(
-           switches::kEnableThreadedCompositing) &&
-       !CommandLine::ForCurrentProcess()->HasSwitch(
-           switches::kDisableThreadedCompositing));
-#endif
-  if (use_echo_for_swap_ack) {
+  if (use_echo_for_swap_ack_) {
     command_buffer_->Echo(base::Bind(
         &WebGraphicsContext3DCommandBufferImpl::OnSwapBuffersComplete,
         weak_ptr_factory_.GetWeakPtr()));