cc: Merge the DrawLayer()/DrawFrame() and SwapBuffers() methods.

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 <utility>
 #include <vector>
 
 #include "base/memory/ptr_util.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/output/context_provider.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/quads/render_pass.h"
 #include "cc/resources/resource_provider.h"
 #include "gpu/command_buffer/client/context_support.h"
-#include "gpu/command_buffer/client/gles2_interface.h"
 
 
 namespace cc {
 
 DelegatingRenderer::DelegatingRenderer(OutputSurface* output_surface,
                                        ResourceProvider* resource_provider)
     : output_surface_(output_surface), resource_provider_(resource_provider) {
   DCHECK(resource_provider_);
 }
 
 DelegatingRenderer::~DelegatingRenderer() = default;
 
-void DelegatingRenderer::DrawFrame(
-    RenderPassList* render_passes_in_draw_order) {
+void DelegatingRenderer::DrawFrame(CompositorFrameMetadata metadata,
+                                   RenderPassList render_passes_in_draw_order) {
   TRACE_EVENT0("cc", "DelegatingRenderer::DrawFrame");
 
-  delegated_frame_data_ = base::WrapUnique(new DelegatedFrameData);
-  DelegatedFrameData& out_data = *delegated_frame_data_;
-  // Move the render passes and resources into the |out_frame|.
-  out_data.render_pass_list.swap(*render_passes_in_draw_order);
-
-  // Collect all resource ids in the render passes into a ResourceIdArray.
+  // Collect all resource ids in the render passes into a single array.
   ResourceProvider::ResourceIdArray resources;
-  for (const auto& render_pass : out_data.render_pass_list) {
+  for (const auto& render_pass : render_passes_in_draw_order) {
     for (auto* quad : render_pass->quad_list) {
       for (ResourceId resource_id : quad->resources)
         resources.push_back(resource_id);
     }
   }
-  resource_provider_->PrepareSendToParent(resources, &out_data.resource_list);
-}
 
-void DelegatingRenderer::SwapBuffers(CompositorFrameMetadata metadata) {
-  TRACE_EVENT0("cc,benchmark", "DelegatingRenderer::SwapBuffers");
+  auto data = base::MakeUnique<DelegatedFrameData>();
+  resource_provider_->PrepareSendToParent(resources, &data->resource_list);
+  data->render_pass_list = std::move(render_passes_in_draw_order);
+
   CompositorFrame compositor_frame;
   compositor_frame.metadata = std::move(metadata);
-  compositor_frame.delegated_frame_data = std::move(delegated_frame_data_);
+  compositor_frame.delegated_frame_data = std::move(data);
   output_surface_->SwapBuffers(std::move(compositor_frame));
 }
 
 }  // namespace cc