cc: Introduce mechanism to observe CompositorFrames submitted to new surfaceIDs

cc/surfaces/surface_factory.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_factory.h"
 
 #include <utility>
 
 #include "base/trace_event/trace_event.h"
 #include "cc/output/compositor_frame.h"
@@ skipping 58 matching lines @@
   }
 }
 
 void SurfaceFactory::SubmitCompositorFrame(const LocalFrameId& local_frame_id,
                                            CompositorFrame frame,
                                            const DrawCallback& callback) {
   TRACE_EVENT0("cc", "SurfaceFactory::SubmitCompositorFrame");
   OwningSurfaceMap::iterator it = surface_map_.find(local_frame_id);
   DCHECK(it != surface_map_.end());
   DCHECK(it->second->factory().get() == this);
+  const CompositorFrame& previous_frame = it->second->GetEligibleFrame();

[vmpstr, 2016/10/11 21:59:04]

Can you add a comment explaining this logic, please?

[Fady Samuel, 2016/10/11 23:11:45]

Done.

+  if (!previous_frame.delegated_frame_data) {
+    float device_scale_factor = frame.metadata.device_scale_factor;
+    gfx::Size frame_size;
+    if (frame.delegated_frame_data &&
+        frame.delegated_frame_data->render_pass_list.size() > 0) {

[vmpstr, 2016/10/11 21:59:04]

nit: !frame.delegated_frame_data->render_pass_list.empty()

[Fady Samuel, 2016/10/11 23:11:45]

Done.

+      frame_size =
+          frame.delegated_frame_data->render_pass_list[0]->output_rect.size();
+    }
+    manager_->SurfaceCreated(it->second->surface_id(), frame_size,
+                             device_scale_factor);
+  }
   it->second->QueueFrame(std::move(frame), callback);
   if (!manager_->SurfaceModified(SurfaceId(frame_sink_id_, local_frame_id))) {
     TRACE_EVENT_INSTANT0("cc", "Damage not visible.", TRACE_EVENT_SCOPE_THREAD);
     it->second->RunDrawCallbacks();
   }
 }
 
 void SurfaceFactory::RequestCopyOfSurface(
     const LocalFrameId& local_frame_id,
     std::unique_ptr<CopyOutputRequest> copy_request) {
@@ skipping 19 matching lines @@
 
 void SurfaceFactory::RefResources(const TransferableResourceArray& resources) {
   holder_.RefResources(resources);
 }
 
 void SurfaceFactory::UnrefResources(const ReturnedResourceArray& resources) {
   holder_.UnrefResources(resources);
 }
 
 }  // namespace cc