Replace VideoRendererBase Get/PutCurrentFrame() with a VideoFrame-containing callback.

webkit/media/webmediaplayer_proxy.cc

Index: webkit/media/webmediaplayer_proxy.cc
diff --git a/webkit/media/webmediaplayer_proxy.cc b/webkit/media/webmediaplayer_proxy.cc
index 3f604b3bd7f9831b28be318ad843edf470b24891..04a32e95b9d0db3f5a11e539e3ef9263c819dd5c 100644
--- a/webkit/media/webmediaplayer_proxy.cc
+++ b/webkit/media/webmediaplayer_proxy.cc
@@ -34,8 +34,11 @@ WebMediaPlayerProxy::~WebMediaPlayerProxy() {
   Detach();
 }
 
-void WebMediaPlayerProxy::Repaint() {
+void WebMediaPlayerProxy::FrameReady(
+    const scoped_refptr<media::VideoFrame>& frame) {
   base::AutoLock auto_lock(lock_);
+  current_frame_ = frame;

[acolwell GONE FROM CHROMIUM, 2013/02/01 00:24:34]

I think you need more code in here to track dropped frames. It seems to me that
there should be some coordination between this function and GetCurrentFrame().
You need to be able to detect how many times current_frame_ gets updated before
another paint actually happens. This would be the number of frames that were
dropped.

[scherkus (not reviewing), 2013/02/01 22:45:25]

As discussed offline, I added back the frame dropping code that was accidentally
removed. The metric is purely based on missed deadlines due to stalls in the
pipeline.

+
   if (outstanding_repaints_ < kMaxOutstandingRepaints) {
     ++outstanding_repaints_;
 
@@ -48,12 +51,11 @@ void WebMediaPlayerProxy::Paint(SkCanvas* canvas,
                                 const gfx::Rect& dest_rect,
                                 uint8_t alpha) {
   DCHECK(render_loop_->BelongsToCurrentThread());
-  if (frame_provider_) {
-    scoped_refptr<media::VideoFrame> video_frame;
-    frame_provider_->GetCurrentFrame(&video_frame);
-    video_renderer_.Paint(video_frame, canvas, dest_rect, alpha);
-    frame_provider_->PutCurrentFrame(video_frame);
-  }
+
+  // Use GetCurrentFrame() to avoid locking while painting in software.
+  scoped_refptr<media::VideoFrame> video_frame;
+  GetCurrentFrame(&video_frame);
+  video_renderer_.Paint(video_frame, canvas, dest_rect, alpha);
 }
 
 bool WebMediaPlayerProxy::HasSingleOrigin() {
@@ -97,14 +99,8 @@ void WebMediaPlayerProxy::RepaintTask() {
 
 void WebMediaPlayerProxy::GetCurrentFrame(
     scoped_refptr<media::VideoFrame>* frame_out) {
-  if (frame_provider_)
-    frame_provider_->GetCurrentFrame(frame_out);
-}
-
-void WebMediaPlayerProxy::PutCurrentFrame(
-    scoped_refptr<media::VideoFrame> frame) {
-  if (frame_provider_)
-    frame_provider_->PutCurrentFrame(frame);
+  base::AutoLock auto_lock(lock_);
+  *frame_out = current_frame_;
 }
 
 }  // namespace webkit_media