cc: Video layers without a frame should not occlude

cc/layers/video_layer_impl.cc

 // Copyright 2011 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 "cc/layers/video_layer_impl.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "cc/layers/video_frame_provider_client_impl.h"
 #include "cc/quads/io_surface_draw_quad.h"
@@ skipping 360 matching lines @@
       resource_provider->DeleteResource(frame_resources_[i]);
     frame_resources_.clear();
   }
 
   provider_client_impl_->PutCurrentFrame();
   frame_ = nullptr;
 
   provider_client_impl_->ReleaseLock();
 }
 
+SimpleEnclosedRegion VideoLayerImpl::VisibleContentOpaqueRegion() const {
+  // If we don't have a frame yet, then we don't have an opaque region.
+  if (!provider_client_impl_->HasCurrentFrame())
+    return SimpleEnclosedRegion();
+  return LayerImpl::VisibleContentOpaqueRegion();
+}
+
 void VideoLayerImpl::ReleaseResources() {
   updater_ = nullptr;
 }
 
 void VideoLayerImpl::SetNeedsRedraw() {
   SetUpdateRect(gfx::UnionRects(update_rect(), gfx::Rect(bounds())));
   layer_tree_impl()->SetNeedsRedraw();
 }
 
 const char* VideoLayerImpl::LayerTypeAsString() const {
   return "cc::VideoLayerImpl";
 }
 
 }  // namespace cc