OnDrawHardware() implementation with async messages

android_webview/browser/hardware_renderer.cc

 // Copyright 2014 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 "android_webview/browser/hardware_renderer.h"
 
 #include <utility>
 
 #include "android_webview/browser/aw_gl_surface.h"
 #include "android_webview/browser/aw_render_thread_context_provider.h"
@@ skipping 162 matching lines @@
 }
 
 void HardwareRenderer::SetBackingFrameBufferObject(
     int framebuffer_binding_ext) {
   surfaces_->SetBackingFrameBufferObject(framebuffer_binding_ext);
 }
 
 void HardwareRenderer::ReturnResourcesInChildFrame() {
   if (child_frame_.get() && child_frame_->frame.get()) {
     cc::ReturnedResourceArray resources_to_return;
+    DCHECK(child_frame_->frame->delegated_frame_data);
     cc::TransferableResource::ReturnResources(
         child_frame_->frame->delegated_frame_data->resource_list,
         &resources_to_return);
 
     // The child frame's compositor id is not necessarily same as
     // compositor_id_.
     ReturnResourcesToCompositor(resources_to_return,
                                 child_frame_->compositor_id,
                                 child_frame_->output_surface_id);
   }
   child_frame_.reset();
 }
 
 void HardwareRenderer::ReturnResourcesToCompositor(
     const cc::ReturnedResourceArray& resources,
     const CompositorID& compositor_id,
     uint32_t output_surface_id) {
   if (output_surface_id != last_committed_output_surface_id_)
     return;
   render_thread_manager_->InsertReturnedResourcesOnRT(resources, compositor_id,
                                                       output_surface_id);
 }
 
 }  // namespace android_webview