cc: Toward merging DrawFrame and SwapBuffers in DelegatingRenderer.

cc/trees/proxy_impl.cc

 // Copyright 2015 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/trees/proxy_impl.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/auto_reset.h"
@@ skipping 596 matching lines @@
   DrawResult result;
   if (layer_tree_host_impl_->CanDraw()) {
     result = layer_tree_host_impl_->PrepareToDraw(&frame);
     draw_frame = forced_draw || result == DRAW_SUCCESS;
   } else {
     result = DRAW_ABORTED_CANT_DRAW;
   }
 
   if (draw_frame) {
     layer_tree_host_impl_->DrawLayers(&frame);
+    if (layer_tree_host_impl_->SwapBuffers(frame))
+      scheduler_->DidSwapBuffers();
     result = DRAW_SUCCESS;
   } else {
     DCHECK_NE(DRAW_SUCCESS, result);
   }
+
   layer_tree_host_impl_->DidDrawAllLayers(frame);
 
   bool start_ready_animations = draw_frame;
   layer_tree_host_impl_->UpdateAnimationState(start_ready_animations);
 
-  if (draw_frame) {
-    if (layer_tree_host_impl_->SwapBuffers(frame))
-      scheduler_->DidSwapBuffers();
-  }
-
   // Tell the main thread that the the newly-commited frame was drawn.
   if (next_frame_is_newly_committed_frame_) {
     next_frame_is_newly_committed_frame_ = false;
     channel_impl_->DidCommitAndDrawFrame();
   }
 
   DCHECK_NE(INVALID_RESULT, result);
   return result;
 }
 
 bool ProxyImpl::IsImplThread() const {
   return task_runner_provider_->IsImplThread();
 }
 
 bool ProxyImpl::IsMainThreadBlocked() const {
   return task_runner_provider_->IsMainThreadBlocked();
 }
 
 ProxyImpl::BlockedMainCommitOnly& ProxyImpl::blocked_main_commit() {
   DCHECK(IsMainThreadBlocked() && commit_completion_event_);
   return main_thread_blocked_commit_vars_unsafe_;
 }
 
 }  // namespace cc