Fix race conditions in window snapshot code.

content/renderer/render_thread_impl.h

 // 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.
 
 #ifndef CONTENT_RENDERER_RENDER_THREAD_IMPL_H_
 #define CONTENT_RENDERER_RENDER_THREAD_IMPL_H_
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/memory/memory_pressure_listener.h"
 #include "base/observer_list.h"
+#include "base/process/process_handle.h"
 #include "base/strings/string16.h"
 #include "base/timer/timer.h"
 #include "build/build_config.h"
 #include "content/child/child_thread.h"
 #include "content/common/content_export.h"
 #include "content/common/gpu/client/gpu_channel_host.h"
 #include "content/common/gpu/gpu_process_launch_causes.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/renderer/media/renderer_gpu_video_accelerator_factories.h"
 #include "ipc/ipc_channel_proxy.h"
@@ skipping 312 matching lines @@
   HistogramCustomizer* histogram_customizer() {
     return &histogram_customizer_;
   }
 
   void SetFlingCurveParameters(const std::vector<float>& new_touchpad,
                                const std::vector<float>& new_touchscreen);
 
   // Retrieve current gamepad data.
   void SampleGamepads(WebKit::WebGamepads* data);
 
+  // Get the browser process's notion of the renderer process's ID.
+  // This is the first argument to RenderWidgetHost::FromID. Ideally
+  // this would be available on all platforms via base::Process.
+  base::ProcessId renderer_process_id() const;
+
  private:
   // ChildThread
   virtual bool OnControlMessageReceived(const IPC::Message& msg) OVERRIDE;
 
   // GpuChannelHostFactory implementation:
   virtual bool IsMainThread() OVERRIDE;
   virtual base::MessageLoop* GetMainLoop() OVERRIDE;
   virtual scoped_refptr<base::MessageLoopProxy> GetIOLoopProxy() OVERRIDE;
   virtual base::WaitableEvent* GetShutDownEvent() OVERRIDE;
   virtual scoped_ptr<base::SharedMemory> AllocateSharedMemory(
@@ skipping 11 matching lines @@
 
   void OnSetZoomLevelForCurrentURL(const std::string& scheme,
                                    const std::string& host,
                                    double zoom_level);
   void OnCreateNewView(const ViewMsg_New_Params& params);
   void OnTransferBitmap(const SkBitmap& bitmap, int resource_id);
   void OnPurgePluginListCache(bool reload_pages);
   void OnNetworkStateChanged(bool online);
   void OnGetAccessibilityTree();
   void OnTempCrashWithData(const GURL& data);
+  void OnSetRendererProcessID(base::ProcessId process_id);
   void OnSetWebKitSharedTimersSuspended(bool suspend);
   void OnMemoryPressure(
       base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level);
 
   void IdleHandlerInForegroundTab();
 
   scoped_ptr<WebGraphicsContext3DCommandBufferImpl> CreateOffscreenContext3d();
 
   // These objects live solely on the render thread.
   scoped_ptr<AppCacheDispatcher> appcache_dispatcher_;
@@ skipping 92 matching lines @@
   scoped_ptr<media::AudioHardwareConfig> audio_hardware_config_;
 
   HistogramCustomizer histogram_customizer_;
 
   scoped_ptr<base::MemoryPressureListener> memory_pressure_listener_;
 
   scoped_ptr<WebRTCIdentityService> webrtc_identity_service_;
 
   scoped_ptr<GamepadSharedMemoryReader> gamepad_shared_memory_reader_;
 
+  base::ProcessId renderer_process_id_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderThreadImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_THREAD_IMPL_H_