cc: Don't do CompositeAndReadback when using DelegatingRenderer.

cc/output/delegating_renderer.cc

 // Copyright 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 "cc/output/delegating_renderer.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/debug/trace_event.h"
 #include "base/string_util.h"
 #include "base/strings/string_split.h"
-#include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
 #include "cc/quads/checkerboard_draw_quad.h"
 #include "cc/quads/debug_border_draw_quad.h"
 #include "cc/quads/render_pass.h"
 #include "cc/quads/render_pass_draw_quad.h"
 #include "cc/quads/solid_color_draw_quad.h"
 #include "cc/quads/texture_draw_quad.h"
 #include "cc/quads/tile_draw_quad.h"
 #include "cc/quads/yuv_video_draw_quad.h"
 #include "cc/resources/resource_provider.h"
@@ skipping 91 matching lines @@
 
   return true;
 }
 
 DelegatingRenderer::~DelegatingRenderer() {}
 
 const RendererCapabilities& DelegatingRenderer::Capabilities() const {
   return capabilities_;
 }
 
+bool DelegatingRenderer::CanReadPixels() const { return false; }
+
 static ResourceProvider::ResourceId AppendToArray(
     ResourceProvider::ResourceIdArray* array,
     ResourceProvider::ResourceId id) {
   array->push_back(id);
   return id;
 }
 
 void DelegatingRenderer::DrawFrame(
     RenderPassList* render_passes_in_draw_order) {
   TRACE_EVENT0("cc", "DelegatingRenderer::DrawFrame");
-  render_passes_for_swap_buffers_.swap(*render_passes_in_draw_order);
-  render_passes_in_draw_order->clear();
-}
 
-void DelegatingRenderer::SwapBuffers(const LatencyInfo& latency_info) {
-  TRACE_EVENT0("cc", "DelegatingRenderer::SwapBuffers");
+  DCHECK(!frame_for_swap_buffers_.delegated_frame_data);
 
-  CompositorFrame out_frame;
-  out_frame.metadata = client_->MakeCompositorFrameMetadata();
+  frame_for_swap_buffers_.metadata = client_->MakeCompositorFrameMetadata();
 
-  out_frame.delegated_frame_data = make_scoped_ptr(new DelegatedFrameData);
-  DelegatedFrameData& out_data = *out_frame.delegated_frame_data;
+  frame_for_swap_buffers_.delegated_frame_data =
+      make_scoped_ptr(new DelegatedFrameData);
+  DelegatedFrameData& out_data = *frame_for_swap_buffers_.delegated_frame_data;
   // Move the render passes and resources into the |out_frame|.
-  out_data.render_pass_list.swap(render_passes_for_swap_buffers_);
+  out_data.render_pass_list.swap(*render_passes_in_draw_order);
 
   // Collect all resource ids in the render passes into a ResourceIdArray.
   ResourceProvider::ResourceIdArray resources;
   DrawQuad::ResourceIteratorCallback append_to_array =
       base::Bind(&AppendToArray, &resources);
   for (size_t i = 0; i < out_data.render_pass_list.size(); ++i) {
     RenderPass* render_pass = out_data.render_pass_list.at(i);
     for (size_t j = 0; j < render_pass->quad_list.size(); ++j)
       render_pass->quad_list[j]->IterateResources(append_to_array);
   }
   resource_provider_->PrepareSendToParent(resources, &out_data.resource_list);
+}
 
-  output_surface_->SendFrameToParentCompositor(&out_frame);
+void DelegatingRenderer::SwapBuffers(const LatencyInfo& latency_info) {
+  TRACE_EVENT0("cc", "DelegatingRenderer::SwapBuffers");
+
+  output_surface_->SendFrameToParentCompositor(&frame_for_swap_buffers_);
+  DCHECK(!frame_for_swap_buffers_.delegated_frame_data);
 }
 
 void DelegatingRenderer::GetFramebufferPixels(void* pixels, gfx::Rect rect) {
-  NOTIMPLEMENTED();
+  NOTREACHED();
 }
 
 void DelegatingRenderer::ReceiveCompositorFrameAck(
     const CompositorFrameAck& ack) {
   resource_provider_->ReceiveFromParent(ack.resources);
 }
 
 
 bool DelegatingRenderer::IsContextLost() {
   WebGraphicsContext3D* context3d = resource_provider_->GraphicsContext3D();
   if (!context3d)
     return false;
   return context3d->getGraphicsResetStatusARB() != GL_NO_ERROR;
 }
 
 void DelegatingRenderer::SetVisible(bool visible) {
   visible_ = visible;
 }
 
 }  // namespace cc