Android: Attach hidden layer for CopyFromCompositingSurface()

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 732 matching lines @@
   // context was lost.
   if (host_->visible())
     host_->SetNeedsCommit();
   client_->OnSwapBuffersCompleted(0);
 }
 
 void CompositorImpl::DidCommit() {
   root_window_->OnCompositingDidCommit();
 }
 
+void CompositorImpl::AttachLayerForReadback(scoped_refptr<cc::Layer> layer) {
+  root_window_->GetLayer()->AddChild(layer);
+}
+
 void CompositorImpl::RequestCopyOfOutputOnRootLayer(
     std::unique_ptr<cc::CopyOutputRequest> request) {
   root_window_->GetLayer()->RequestCopyOfOutput(std::move(request));
 }
 
 void CompositorImpl::OnVSync(base::TimeTicks frame_time,
                              base::TimeDelta vsync_period) {
   FOR_EACH_OBSERVER(VSyncObserver, observer_list_,
                     OnVSync(frame_time, vsync_period));
   if (needs_begin_frames_)
@@ skipping 12 matching lines @@
 void CompositorImpl::SetNeedsAnimate() {
   needs_animate_ = true;
   if (!host_->visible())
     return;
 
   TRACE_EVENT0("compositor", "Compositor::SetNeedsAnimate");
   host_->SetNeedsAnimate();
 }
 
 }  // namespace content