Add playback underflow logic to media::VideoRendererImpl.

media/filters/video_renderer_impl.cc

Index: media/filters/video_renderer_impl.cc
diff --git a/media/filters/video_renderer_impl.cc b/media/filters/video_renderer_impl.cc
index 57be35d0010fd8cb6d9a46a23fca855081c0bce3..1cbf1bcdb90dea0c0901a5fca295fec44e2c9485 100644
--- a/media/filters/video_renderer_impl.cc
+++ b/media/filters/video_renderer_impl.cc
@@ -221,9 +221,15 @@ void VideoRendererImpl::ThreadMain() {
 
     // Remain idle until we have the next frame ready for rendering.
     if (ready_frames_.empty()) {
-      if (received_end_of_stream_ && !rendered_end_of_stream_) {
-        rendered_end_of_stream_ = true;
-        ended_cb_.Run();
+      if (received_end_of_stream_) {
+        if (!rendered_end_of_stream_) {
+          rendered_end_of_stream_ = true;
+          ended_cb_.Run();
+        }
+      } else {
+        buffering_state_ = BUFFERING_HAVE_NOTHING;
+        task_runner_->PostTask(
+            FROM_HERE, base::Bind(buffering_state_cb_, BUFFERING_HAVE_NOTHING));
       }
 
       UpdateStatsAndWait_Locked(kIdleTimeDelta);