Re-land of http://codereview.chromium.org/6094009 with Mac build fix....

chrome/gpu/gpu_thread.h

 // Copyright (c) 2010 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.
 
 #ifndef CHROME_GPU_GPU_THREAD_H_
 #define CHROME_GPU_GPU_THREAD_H_
 #pragma once
 
 #include "base/basictypes.h"
+#include "base/command_line.h"
 #include "base/scoped_ptr.h"
 #include "base/time.h"
 #include "build/build_config.h"
 #include "chrome/common/child_thread.h"
 #include "chrome/common/gpu_info.h"
 #include "chrome/gpu/gpu_channel.h"
 #include "chrome/gpu/gpu_config.h"
 #include "chrome/gpu/x_util.h"
 #include "gfx/native_widget_types.h"
 
 namespace IPC {
 struct ChannelHandle;
 }
 
+class GpuWatchdogThread;
+
 class GpuThread : public ChildThread {
  public:
-  GpuThread();
+  explicit GpuThread(const CommandLine& command_line);
   ~GpuThread();
 
   void Init(const base::Time& process_start_time);
+  void StopWatchdog();
 
   // Remove the channel for a particular renderer.
   void RemoveChannel(int renderer_id);
 
  private:
   // ChildThread overrides.
   virtual bool OnControlMessageReceived(const IPC::Message& msg);
 
   // Message handlers.
+  void OnInitialize();
   void OnEstablishChannel(int renderer_id);
   void OnCloseChannel(const IPC::ChannelHandle& channel_handle);
   void OnSynchronize();
   void OnCollectGraphicsInfo();
 #if defined(OS_MACOSX)
   void OnAcceleratedSurfaceBuffersSwappedACK(
       int renderer_id, int32 route_id, uint64 swap_buffers_count);
   void OnDidDestroyAcceleratedSurface(int renderer_id, int32 renderer_route_id);
 #endif
   void OnCrash();
   void OnHang();
 
 #if defined(OS_WIN)
   static void CollectDxDiagnostics(GpuThread* thread);
   static void SetDxDiagnostics(GpuThread* thread, const DxDiagNode& node);
 #endif
 
+  CommandLine command_line_;
+  base::Time process_start_time_;
+  scoped_refptr<GpuWatchdogThread> watchdog_thread_;
+
   typedef base::hash_map<int, scoped_refptr<GpuChannel> > GpuChannelMap;
   GpuChannelMap gpu_channels_;
 
   // Information about the GPU, such as device and vendor ID.
   GPUInfo gpu_info_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuThread);
 };
 
 #endif  // CHROME_GPU_GPU_THREAD_H_