Set content opacity of DFHAndroid surfacelayer based on renderer frame contents.

content/browser/renderer_host/compositor_impl_android.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/compositor_impl_android.h"
 
 #include <android/bitmap.h>
 #include <android/native_window_jni.h>
 #include <stdint.h>
 #include <unordered_set>
@@ skipping 491 matching lines @@
   params.main_task_runner = base::ThreadTaskRunnerHandle::Get();
   params.settings = &settings;
   params.animation_host = cc::AnimationHost::CreateMainInstance();
   host_ = cc::LayerTreeHost::CreateSingleThreaded(this, &params);
   DCHECK(!host_->visible());
   host_->GetLayerTree()->SetRootLayer(root_window_->GetLayer());
   host_->set_surface_client_id(surface_id_allocator_->client_id());
   host_->GetLayerTree()->SetViewportSize(size_);
   host_->GetLayerTree()->set_has_transparent_background(
       has_transparent_background_);
+  host_->GetLayerTree()->set_background_color(SK_ColorBLACK);
   host_->GetLayerTree()->SetDeviceScaleFactor(device_scale_factor_);
 
   if (needs_animate_)
     host_->SetNeedsAnimate();
 }
 
 void CompositorImpl::SetVisible(bool visible) {
   TRACE_EVENT1("cc", "CompositorImpl::SetVisible", "visible", visible);
   if (!visible) {
     DCHECK(host_->visible());
@@ skipping 293 matching lines @@
 
   TRACE_EVENT0("compositor", "Compositor::SetNeedsAnimate");
   host_->SetNeedsAnimate();
 }
 
 bool CompositorImpl::HavePendingReadbacks() {
   return !readback_layer_tree_->children().empty();
 }
 
 }  // namespace content