Add LatencyInfo support for Surfaces.

cc/surfaces/surface.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 "cc/surfaces/surface.h"
 
 #include "cc/output/compositor_frame.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/surfaces/surface_factory.h"
 
@@ skipping 15 matching lines @@
     ReturnedResourceArray current_resources;
     TransferableResource::ReturnResources(
         current_frame_->delegated_frame_data->resource_list,
         &current_resources);
     factory_->UnrefResources(current_resources);
   }
 }
 
 void Surface::QueueFrame(scoped_ptr<CompositorFrame> frame,
                          const base::Closure& callback) {
+  TakeLatencyInfo(&frame->metadata.latency_info);
   scoped_ptr<CompositorFrame> previous_frame = current_frame_.Pass();
   current_frame_ = frame.Pass();
   factory_->ReceiveFromChild(
       current_frame_->delegated_frame_data->resource_list);
   ++frame_index_;
 
   if (previous_frame) {
     ReturnedResourceArray previous_resources;
     TransferableResource::ReturnResources(
         previous_frame->delegated_frame_data->resource_list,
         &previous_resources);
     factory_->UnrefResources(previous_resources);
   }
   if (!draw_callback_.is_null())
     draw_callback_.Run();
   draw_callback_ = callback;
 }
 
 void Surface::RequestCopyOfOutput(scoped_ptr<CopyOutputRequest> copy_request) {
   // TODO(jbauman): Make this work.
   copy_request->SendEmptyResult();
 }
 
 const CompositorFrame* Surface::GetEligibleFrame() {
   return current_frame_.get();
 }
 
+void Surface::TakeLatencyInfo(std::vector<ui::LatencyInfo>* latency_info) {
+  if (!current_frame_)
+    return;
+  std::copy(current_frame_->metadata.latency_info.begin(),

[jamesr, 2014/09/02 19:04:28]

if we expect the dest to be empty (which i think it normally is for QueueFrame)
it'd be more efficient to swap() the vectors in that case

+            current_frame_->metadata.latency_info.end(),
+            std::back_inserter(*latency_info));
+  current_frame_->metadata.latency_info.clear();
+}
+
 void Surface::RunDrawCallbacks() {
   if (!draw_callback_.is_null()) {
     base::Closure callback = draw_callback_;
     draw_callback_ = base::Closure();
     callback.Run();
   }
 }
 
 }  // namespace cc