Make RendererGpuVideoDecoderFactories live on arbitrary threads.

content/renderer/media/rtc_video_decoder_factory.h

Index: content/renderer/media/rtc_video_decoder_factory.h
diff --git a/content/renderer/media/rtc_video_decoder_factory.h b/content/renderer/media/rtc_video_decoder_factory.h
index 1974701cf58867fdea5b5cd98af8addbd29c9700..ae4d1e0e137f6599a8abc877261eead41f2bdbbe 100644
--- a/content/renderer/media/rtc_video_decoder_factory.h
+++ b/content/renderer/media/rtc_video_decoder_factory.h
@@ -8,7 +8,6 @@
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/threading/thread.h"
 #include "content/common/content_export.h"
-#include "media/filters/gpu_video_decoder.h"
 #include "third_party/libjingle/source/talk/media/webrtc/webrtcvideodecoderfactory.h"
 #include "third_party/webrtc/modules/video_coding/codecs/interface/video_codec_interface.h"
 
@@ -17,12 +16,14 @@ class VideoDecoder;
 }
 
 namespace content {
+class RendererGpuVideoDecoderFactories;
 
+// TODO(wuchengli): add unittest.
 class CONTENT_EXPORT RTCVideoDecoderFactory
     : NON_EXPORTED_BASE(public cricket::WebRtcVideoDecoderFactory) {
  public:
-  RTCVideoDecoderFactory(
-      const scoped_refptr<media::GpuVideoDecoder::Factories>& gpu_factories);
+  explicit RTCVideoDecoderFactory(
+      const scoped_refptr<RendererGpuVideoDecoderFactories>& gpu_factories);
   virtual ~RTCVideoDecoderFactory();
 
   // Runs on Chrome_libJingle_WorkerThread. The child thread is blocked while
@@ -35,8 +36,7 @@ class CONTENT_EXPORT RTCVideoDecoderFactory
   virtual void DestroyVideoDecoder(webrtc::VideoDecoder* decoder) OVERRIDE;
 
  private:
-  scoped_refptr<base::MessageLoopProxy> vda_loop_proxy_;
-  scoped_ptr<webrtc::VideoDecoder> decoder_;
+  scoped_refptr<RendererGpuVideoDecoderFactories> gpu_factories_;
 
   DISALLOW_COPY_AND_ASSIGN(RTCVideoDecoderFactory);
 };