Revert of Remove threading from RendererGpuVideoAcceleratorFactories

content/renderer/media/rtc_video_decoder.h

Index: content/renderer/media/rtc_video_decoder.h
diff --git a/content/renderer/media/rtc_video_decoder.h b/content/renderer/media/rtc_video_decoder.h
index 9bc9849fa0d3bc5cc98a9036df5ede42b506f895..0d99a4c8c802665d7d6c8f6d306e5f54bab96609 100644
--- a/content/renderer/media/rtc_video_decoder.h
+++ b/content/renderer/media/rtc_video_decoder.h
@@ -6,7 +6,6 @@
 #define CONTENT_RENDERER_MEDIA_RTC_VIDEO_DECODER_H_
 
 #include <deque>
-#include <list>
 #include <map>
 #include <set>
 #include <utility>
@@ -14,7 +13,9 @@
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/weak_ptr.h"
+#include "base/message_loop/message_loop.h"
 #include "base/synchronization/lock.h"
+#include "base/synchronization/waitable_event.h"
 #include "base/threading/thread.h"
 #include "content/common/content_export.h"
 #include "media/base/bitstream_buffer.h"
@@ -24,7 +25,6 @@
 #include "third_party/webrtc/modules/video_coding/codecs/interface/video_codec_interface.h"
 
 namespace base {
-class WaitableEvent;
 class MessageLoopProxy;
 };
 
@@ -43,7 +43,8 @@
 // frames are delivered to WebRTC on |vda_message_loop_|.
 class CONTENT_EXPORT RTCVideoDecoder
     : NON_EXPORTED_BASE(public webrtc::VideoDecoder),
-      public media::VideoDecodeAccelerator::Client {
+      public media::VideoDecodeAccelerator::Client,
+      public base::MessageLoop::DestructionObserver {
  public:
   virtual ~RTCVideoDecoder();
 
@@ -86,6 +87,10 @@
   virtual void NotifyResetDone() OVERRIDE;
   virtual void NotifyError(media::VideoDecodeAccelerator::Error error) OVERRIDE;
 
+  // base::DestructionObserver implementation. Called when |vda_message_loop_|
+  // is stopped.
+  virtual void WillDestroyCurrentMessageLoop() OVERRIDE;
+
  private:
   class SHMBuffer;
   // Metadata of a bitstream buffer.
@@ -111,6 +116,8 @@
   RTCVideoDecoder(
       const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories);
 
+  void Initialize(base::WaitableEvent* waiter);
+
   // Requests a buffer to be decoded by VDA.
   void RequestBufferDecode();
 
@@ -150,9 +157,6 @@
 
   // Tells VDA that a picture buffer can be recycled.
   void ReusePictureBuffer(int64 picture_buffer_id, uint32 sync_point);
-
-  // Create |vda_| on |vda_loop_proxy_|.
-  void CreateVDA(media::VideoCodecProfile profile, base::WaitableEvent* waiter);
 
   void DestroyTextures();
   void DestroyVDA();