aw: Fix effective frame source leak after detach

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 138 matching lines @@
   DCHECK(child_id_.is_null());
   DCHECK(surface_factory_);
   child_id_ = surface_id_allocator_->GenerateId();
   surface_factory_->Create(child_id_);
   surfaces_->AddChildId(cc::SurfaceId(frame_sink_id_, child_id_));
 }
 
 void HardwareRenderer::DestroySurface() {
   DCHECK(!child_id_.is_null());
   DCHECK(surface_factory_);
+
+  // Submit an empty frame to force any existing resources to be returned.
+  cc::CompositorFrame empty_frame;
+  empty_frame.delegated_frame_data =
+      base::WrapUnique(new cc::DelegatedFrameData);
+  surface_factory_->SubmitCompositorFrame(child_id_, std::move(empty_frame),
+                                          cc::SurfaceFactory::DrawCallback());
+
   surfaces_->RemoveChildId(cc::SurfaceId(frame_sink_id_, child_id_));
   surface_factory_->Destroy(child_id_);
   child_id_ = cc::LocalFrameId();
 }
 
 void HardwareRenderer::ReturnResources(
     const cc::ReturnedResourceArray& resources) {
   ReturnResourcesToCompositor(resources, compositor_id_,
                               last_submitted_compositor_frame_sink_id_);
 }
@@ skipping 23 matching lines @@
     const cc::ReturnedResourceArray& resources,
     const CompositorID& compositor_id,
     uint32_t compositor_frame_sink_id) {
   if (compositor_frame_sink_id != last_committed_compositor_frame_sink_id_)
     return;
   render_thread_manager_->InsertReturnedResourcesOnRT(resources, compositor_id,
                                                       compositor_frame_sink_id);
 }
 
 }  // namespace android_webview