Ignore sink start attempts when no frames are present.

media/renderers/video_renderer_impl_unittest.cc

Index: media/renderers/video_renderer_impl_unittest.cc
diff --git a/media/renderers/video_renderer_impl_unittest.cc b/media/renderers/video_renderer_impl_unittest.cc
index 41c751f9c158e33e5c94093f85332cbcc6d2fd1c..e6a8c9ac9d144c54db5ae399cc979a1338ea2468 100644
--- a/media/renderers/video_renderer_impl_unittest.cc
+++ b/media/renderers/video_renderer_impl_unittest.cc
@@ -339,6 +339,10 @@ class VideoRendererImplTest
       Mock::VerifyAndClearExpectations(&mock_cb_);
     }
 
+    // Simulate delayed buffering state callbacks.
+    renderer_->OnTimeStateChanged(false);
+    renderer_->OnTimeStateChanged(true);
+
     // Receiving end of stream should signal having enough.
     {
       SCOPED_TRACE("Waiting for BUFFERING_HAVE_ENOUGH");