[DO NOT COMMIT] Initial MediaPlayerRenderer plumbing and basic features

media/base/renderer_client.h

 // Copyright 2016 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 MEDIA_BASE_RENDERER_CLIENT_H_
 #define MEDIA_BASE_RENDERER_CLIENT_H_
 
+#include "base/time/time.h"
 #include "media/base/pipeline_status.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace media {
 
-// Interface used by Renderer, AudioRenderer, and VideoRenderer implementations
-// to notify their clients.
+// Interface used by Renderer, AudioRenderer, VideoRenderer and
+// MediaPlayerRenderer implementations to notify their clients.
 class RendererClient {
  public:
   // Executed if any error was encountered after Renderer initialization.
   virtual void OnError(PipelineStatus status) = 0;
 
   // Executed when rendering has reached the end of stream.
   virtual void OnEnded() = 0;
 
   // Executed periodically with rendering statistics.
   virtual void OnStatisticsUpdate(const PipelineStatistics& stats) = 0;
 
   // Executed when buffering state is changed.
   virtual void OnBufferingStateChange(BufferingState state) = 0;
 
   // Executed whenever the key needed to decrypt the stream is not available.
   virtual void OnWaitingForDecryptionKey() = 0;
 
   // Executed for the first video frame and whenever natural size changes.
   // Only used if media stream contains video track.
   virtual void OnVideoNaturalSizeChange(const gfx::Size& size) = 0;
 
   // Executed for the first video frame and whenever opacity changes.
   // Only used if media stream contains video track.
   virtual void OnVideoOpacityChange(bool opaque) = 0;
+
+  // Executed when video metadata is first read, and whenever it changes.
+  // Only used when we are using a URL demuxer (e.g. for MediaPlayerRenderer).
+  virtual void OnDurationChange(base::TimeDelta duration) = 0;

[xhwang, 2016/06/22 17:39:02]

As discussed offline, this change sgtm :) Now we have two sources of duration
(from Renderer and from Demuxer). Somewhere we need to document about what the
expectation is. For example, we shouldn't get duration change from both sources.

 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_RENDERER_CLIENT_H_