corresponding change in CaptureVideoDecoder and RTCVideoDecoder due to pull model used in medi...

content/renderer/media/capture_video_decoder.cc

Index: content/renderer/media/capture_video_decoder.cc
===================================================================
--- content/renderer/media/capture_video_decoder.cc	(revision 109978)
+++ content/renderer/media/capture_video_decoder.cc	(working copy)
@@ -67,6 +67,13 @@
                  this, callback));
 }
 
+void CaptureVideoDecoder::Flush(const base::Closure& callback) {
+  message_loop_proxy_->PostTask(
+      FROM_HERE,
+      base::Bind(&CaptureVideoDecoder::FlushOnDecoderThread,
+                 this, callback));
+}
+
 void CaptureVideoDecoder::Stop(const base::Closure& callback) {
   message_loop_proxy_->PostTask(
       FROM_HERE,
@@ -141,8 +148,12 @@
 
 void CaptureVideoDecoder::ReadOnDecoderThread(const ReadCB& callback) {
   DCHECK(message_loop_proxy_->BelongsToCurrentThread());
-  CHECK(read_cb_.is_null());
-  read_cb_ = callback;
+  CHECK(!callback.is_null());
+  if (state_ != kNormal) {
+    DeliverBlackFrame(callback);
+    return;
+  }
+  read_cbs_.push(callback);
 }
 
 void CaptureVideoDecoder::PlayOnDecoderThread(const base::Closure& callback) {
@@ -158,6 +169,16 @@
   media::VideoDecoder::Pause(callback);
 }
 
+void CaptureVideoDecoder::FlushOnDecoderThread(const base::Closure& callback) {
+  DVLOG(1) << "FlushOnDecoderThread";
+  DCHECK(message_loop_proxy_->BelongsToCurrentThread());
+  while (!read_cbs_.empty()) {
+    DeliverBlackFrame(read_cbs_.front());
+    read_cbs_.pop();
+  }
+  media::VideoDecoder::Flush(callback);
+}
+
 void CaptureVideoDecoder::StopOnDecoderThread(const base::Closure& callback) {
   DVLOG(1) << "StopOnDecoderThread";
   DCHECK(message_loop_proxy_->BelongsToCurrentThread());
@@ -201,7 +222,7 @@
     scoped_refptr<media::VideoCapture::VideoFrameBuffer> buf) {
   DCHECK(message_loop_proxy_->BelongsToCurrentThread());
 
-  if (read_cb_.is_null() || kNormal != state_) {
+  if (read_cbs_.empty() || kNormal != state_) {
     capture->FeedBuffer(buf);
     return;
   }
@@ -240,14 +261,16 @@
   buffer += uv_width * uv_height;
   CopyVPlane(buffer, uv_width, uv_height, video_frame);
 
-  DeliverFrame(video_frame);
+  read_cbs_.front().Run(video_frame);
+  read_cbs_.pop();
   capture->FeedBuffer(buf);
 }
 
-void CaptureVideoDecoder::DeliverFrame(
-    const scoped_refptr<media::VideoFrame>& video_frame) {
-  // Reset the callback before running to protect against reentrancy.
-  ReadCB read_cb = read_cb_;
-  read_cb_.Reset();
+void CaptureVideoDecoder::DeliverBlackFrame(
+    const ReadCB& read_cb) {
+  CHECK(!read_cb.is_null());
+  scoped_refptr<media::VideoFrame> video_frame =
+      media::VideoFrame::CreateBlackFrame(natural_size_.width(),
+                                          natural_size_.height());
   read_cb.Run(video_frame);
 }