Added GL_CHROMIUM_trace_marker feature as well as gpu_toplevel markers.

content/common/gpu/client/context_provider_command_buffer.cc

Index: content/common/gpu/client/context_provider_command_buffer.cc
diff --git a/content/common/gpu/client/context_provider_command_buffer.cc b/content/common/gpu/client/context_provider_command_buffer.cc
index a4c3111c0cea56475463ae9eac507a986afb95b3..6c4882cd13e9cbbcc805ac06c17bcad7264b51e2 100644
--- a/content/common/gpu/client/context_provider_command_buffer.cc
+++ b/content/common/gpu/client/context_provider_command_buffer.cc
@@ -48,7 +48,9 @@ ContextProviderCommandBuffer::Create(
 ContextProviderCommandBuffer::ContextProviderCommandBuffer(
     scoped_ptr<WebGraphicsContext3DCommandBufferImpl> context3d,
     const std::string& debug_name)
-    : context3d_(context3d.Pass()),
+    : gpu_trace_top_level_category_(TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED(
+          TRACE_DISABLED_BY_DEFAULT("gpu_toplevel"))),
+      context3d_(context3d.Pass()),
       debug_name_(debug_name),
       destroyed_(false) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
@@ -96,9 +98,13 @@ bool ContextProviderCommandBuffer::BindToCurrentThread() {
 
   InitializeCapabilities();
 
-  std::string unique_context_name =
-      base::StringPrintf("%s-%p", debug_name_.c_str(), context3d_.get());
-  context3d_->pushGroupMarkerEXT(unique_context_name.c_str());
+  if (*gpu_trace_top_level_category_) {

[vmiura, 2014/12/09 00:18:10]

As in render_widget_host_view_android.cc, move the category checks into the
macros.

+    std::string unique_context_name =
+        base::StringPrintf("%s-%p", debug_name_.c_str(), context3d_.get());
+    TRACE_GPU_EVENT_BEGIN0(context3d_,
+                           TRACE_DISABLED_BY_DEFAULT("gpu_toplevel"),
+                           unique_context_name.c_str());
+  }
 
   lost_context_callback_proxy_.reset(new LostContextCallbackProxy(this));
   context3d_->GetCommandBufferProxy()->SetMemoryAllocationChangedCallback(
@@ -199,6 +205,9 @@ void ContextProviderCommandBuffer::InitializeCapabilities() {
 
 bool ContextProviderCommandBuffer::DestroyedOnMainThread() {
   DCHECK(main_thread_checker_.CalledOnValidThread());
+  if (*gpu_trace_top_level_category_) {
+    TRACE_GPU_EVENT_END0(context3d_);
+  }
 
   base::AutoLock lock(main_thread_lock_);
   return destroyed_;