Remove media::VideoDecodeContext as it has no implementation and is unused.

media/video/video_decode_engine.h

Index: media/video/video_decode_engine.h
diff --git a/media/video/video_decode_engine.h b/media/video/video_decode_engine.h
index c2b1bfaf863401a8f6359f1615b4360b4704e30a..2d52b2450dfde768837b1f80a84e70487a980eb0 100644
--- a/media/video/video_decode_engine.h
+++ b/media/video/video_decode_engine.h
@@ -11,13 +11,9 @@
 #include "media/base/video_decoder_config.h"
 #include "media/base/video_frame.h"
 
-class MessageLoop;
-
 namespace media {
 
 class Buffer;
-class VideoDecodeContext;
-
 struct PipelineStatistics;
 
 class MEDIA_EXPORT VideoDecodeEngine {
@@ -66,17 +62,9 @@ class MEDIA_EXPORT VideoDecodeEngine {
 
   // Initialize the engine with specified configuration.
   //
-  // |decode_context| is used for allocation of VideoFrame.
-  // It is important that |decode_context| is called only on |message_loop|.
-  //
-  // TODO(hclam): Currently refactoring code to use VideoDecodeContext so
-  // |context| may be NULL in some cases.
-  //
   // Engine should call EventHandler::OnInitializeDone() whether the
   // initialization operation finished successfully or not.
-  virtual void Initialize(MessageLoop* message_loop,
-                          EventHandler* event_handler,
-                          VideoDecodeContext* context,
+  virtual void Initialize(EventHandler* event_handler,
                           const VideoDecoderConfig& config) = 0;
 
   // Uninitialize the engine. Engine should destroy all resources and call