cc: Video layers without a frame should not occlude

content/renderer/media/android/webmediaplayer_android.cc

 // Copyright 2013 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.
 
 #include "content/renderer/media/android/webmediaplayer_android.h"
 
 #include <limits>
 
 #include "base/android/build_info.h"
 #include "base/bind.h"
@@ skipping 1262 matching lines @@
   base::AutoLock auto_lock(current_frame_lock_);
   current_frame_ = video_frame;
 }
 
 bool WebMediaPlayerAndroid::UpdateCurrentFrame(base::TimeTicks deadline_min,
                                                base::TimeTicks deadline_max) {
   NOTIMPLEMENTED();
   return false;
 }
 
+bool WebMediaPlayerAndroid::HasCurrentFrame() const {
+  return current_frame_;

[danakj, 2015/05/18 18:15:45]

you need to lock current_frame_lock_ no?

[hendrikw, 2015/05/18 18:33:59]

Yeah, I was unsure about this.  We have a lock in the caller, and
VideoFrameCompositor doesn't lock on the GetCurrentFrame.  
Calling (bool)scoped_ptr is atomic.

I can play it safe and put the locks in here, but I'll lose constness.

Let me know that you think.

[danakj, 2015/05/18 18:44:57]

I /think/ in VFC the lock_ is locking access to the callback_ and not the
current_frame_. I guess it doesn't access the frame from other threads.
What makes you say it's atomic? It's implemented as:

return impl_.get() ? &scoped_ptr::impl_ : nullptr;
I think we need to for correctness.

+}
+
 scoped_refptr<media::VideoFrame> WebMediaPlayerAndroid::GetCurrentFrame() {
   scoped_refptr<VideoFrame> video_frame;
   {
     base::AutoLock auto_lock(current_frame_lock_);
     video_frame = current_frame_;
   }
 
   return video_frame;
 }
 
@@ skipping 564 matching lines @@
 
 bool WebMediaPlayerAndroid::IsHLSStream() const {
   std::string mime;
   GURL url = redirected_url_.is_empty() ? url_ : redirected_url_;
   if (!net::GetMimeTypeFromFile(base::FilePath(url.path()), &mime))
     return false;
   return !mime.compare("application/x-mpegurl");
 }
 
 }  // namespace content