Allow AllocateGpuMemoryBuffer to be called from multiple threads.

content/renderer/render_thread_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_thread_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <vector>
@@ skipping 388 matching lines @@
   base::FilePath media_path;
   PathService::Get(DIR_MEDIA_LIBS, &media_path);
   if (!media_path.empty())
     media::InitializeMediaLibrary(media_path);
 
   memory_pressure_listener_.reset(new base::MemoryPressureListener(
       base::Bind(&RenderThreadImpl::OnMemoryPressure, base::Unretained(this))));
 
   renderer_process_id_ = base::kNullProcessId;
 
-  // AllocateGpuMemoryBuffer must be used exclusively on one thread but
-  // it doesn't have to be the same thread RenderThreadImpl is created on.
-  allocate_gpu_memory_buffer_thread_checker_.DetachFromThread();
-
   TRACE_EVENT_END_ETW("RenderThreadImpl::Init", 0, "");
 }
 
 RenderThreadImpl::~RenderThreadImpl() {
 }
 
 void RenderThreadImpl::Shutdown() {
   FOR_EACH_OBSERVER(
       RenderProcessObserver, observers_, OnRenderProcessShutdown());
 
@@ skipping 644 matching lines @@
 }
 
 void RenderThreadImpl::DeleteImage(int32 image_id, int32 sync_point) {
   NOTREACHED();
 }
 
 scoped_ptr<gfx::GpuMemoryBuffer> RenderThreadImpl::AllocateGpuMemoryBuffer(
     size_t width,
     size_t height,
     unsigned internalformat) {
-  DCHECK(allocate_gpu_memory_buffer_thread_checker_.CalledOnValidThread());
-
   if (!GpuMemoryBufferImpl::IsFormatValid(internalformat))
     return scoped_ptr<gfx::GpuMemoryBuffer>();
 
   gfx::GpuMemoryBufferHandle handle;
   bool success;
   IPC::Message* message =
       new ChildProcessHostMsg_SyncAllocateGpuMemoryBuffer(width,
                                                           height,
                                                           internalformat,
                                                           &handle);
@@ skipping 276 matching lines @@
   if (!gamepad_shared_memory_reader_)
     gamepad_shared_memory_reader_.reset(new GamepadSharedMemoryReader);
   gamepad_shared_memory_reader_->SampleGamepads(*data);
 }
 
 base::ProcessId RenderThreadImpl::renderer_process_id() const {
   return renderer_process_id_;
 }
 
 }  // namespace content