Split WebGraphicsContext3DCommandBufferImpl::initialize() into two stages.

content/renderer/gpu/renderer_gl_context.cc

Index: content/renderer/gpu/renderer_gl_context.cc
===================================================================
--- content/renderer/gpu/renderer_gl_context.cc	(revision 98270)
+++ content/renderer/gpu/renderer_gl_context.cc	(working copy)
@@ -10,6 +10,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
 #include "base/memory/weak_ptr.h"
+#include "base/message_loop.h"
 #include "base/shared_memory.h"
 #include "content/common/view_messages.h"
 #include "content/renderer/gpu/command_buffer_proxy.h"
@@ -209,6 +210,7 @@
 
 bool RendererGLContext::MakeCurrent(RendererGLContext* context) {
   if (context) {
+    DCHECK(MessageLoop::current() == context->message_loop_);
     gles2::SetGLContext(context->gles2_implementation_);
 
     // Don't request latest error status from service. Just use the locally
@@ -284,7 +286,11 @@
       transfer_buffer_id_(-1),
       gles2_implementation_(NULL),
       last_error_(SUCCESS),
-      frame_number_(0) {
+      frame_number_(0)
+#ifndef NDEBUG
+      , message_loop_(MessageLoop::current())
+#endif
+{
   DCHECK(channel);
 }
 
@@ -297,6 +303,7 @@
                                    const char* allowed_extensions,
                                    const int32* attrib_list,
                                    const GURL& active_url) {
+  DCHECK(MessageLoop::current() == message_loop_);
   DCHECK(size.width() >= 0 && size.height() >= 0);
   TRACE_EVENT2("gpu", "RendererGLContext::Initialize",
                    "on_screen", onscreen, "num_pixels", size.GetArea());
@@ -415,6 +422,7 @@
 
 void RendererGLContext::Destroy() {
   TRACE_EVENT0("gpu", "RendererGLContext::Destroy");
+  DCHECK(MessageLoop::current() == message_loop_);
   SetParent(NULL);
 
   if (gles2_implementation_) {