RTCVideoDecoder: add Destroy() static method for RTCVideoDecoderFactory

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 56ee543cfc1b9f91d66bd231614fbfa294155bfa..b96779af04eba58a2b2cfc31b90b8138700cbd55 100644
--- a/content/renderer/media/rtc_video_decoder.h
+++ b/content/renderer/media/rtc_video_decoder.h
@@ -51,11 +51,14 @@ class CONTENT_EXPORT RTCVideoDecoder
  public:
   ~RTCVideoDecoder() override;
 
-  // Creates a RTCVideoDecoder. Returns NULL if failed. The video decoder will
-  // run on the message loop of |factories|.
+  // Creates a RTCVideoDecoder on the message loop of |factories|. Returns NULL
+  // if failed. The video decoder will run on the message loop of |factories|.
   static scoped_ptr<RTCVideoDecoder> Create(
       webrtc::VideoCodecType type,
       media::GpuVideoAcceleratorFactories* factories);
+  // Destroys |decoder| on the loop of |factories|
+  static void Destroy(webrtc::VideoDecoder* decoder,
+                      media::GpuVideoAcceleratorFactories* factories);
 
   // webrtc::VideoDecoder implementation.
   // Called on WebRTC DecodingThread.