Remove requirement of compositing a video frame for dropped frame count.

content/renderer/media/video_frame_compositor.h

 // Copyright 2014 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 CONTENT_RENDERER_MEDIA_VIDEO_FRAME_COMPOSITOR_H_
 #define CONTENT_RENDERER_MEDIA_VIDEO_FRAME_COMPOSITOR_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
@@ skipping 34 matching lines @@
       const scoped_refptr<base::SingleThreadTaskRunner>& compositor_task_runner,
       const base::Callback<void(gfx::Size)>& natural_size_changed_cb);
   ~VideoFrameCompositor();
 
   cc::VideoFrameProvider* GetVideoFrameProvider();
 
   // Updates the current frame and notifies the compositor.
   void UpdateCurrentFrame(const scoped_refptr<media::VideoFrame>& frame);
 
   // Retrieves the last frame set via UpdateCurrentFrame() for non-compositing
-  // purposes (e.g., painting to a canvas). Frames retrieved in this manner will
-  // not be counted as being composited for frame drop counting.
+  // purposes (e.g., painting to a canvas).
   //
   // Note that the compositor retrieves frames via the cc::VideoFrameProvider
   // interface instead of using this method.
   scoped_refptr<media::VideoFrame> GetCurrentFrame();
 
-  // Returns the number of frames dropped before the compositor was notified as
-  // well as being able to composite the previous frame.
+  // Returns the number of frames dropped before the compositor was notified
+  // of a new frame.
   uint32 GetFramesDroppedBeforeComposite();

[xhwang, 2014/03/27 21:28:59]

The name is not accurate now. "BeforeComposite" should really be
"BeforeCompositorIsNotified". Previously a frame is counted as dropped if it's
updated before the frame is composited. Now we don't care whether it's
composited or not.

That being said, I don't have a good naming suggestion yet... Probably just drop
the "BeforeComposite" part?

[scherkus (not reviewing), 2014/03/29 00:34:14]

let's go with the extremely long but accurate name

I feel it's OK for something like this where it's extremely important to
understand exactly what we're measuring

 
   void SetFramesDroppedBeforeCompositeForTesting(uint32 dropped_frames);
 
  private:
   class Internal;
   Internal* internal_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoFrameCompositor);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_VIDEO_FRAME_COMPOSITOR_H_