Enforce constant size and device scale factor for surfaces

content/browser/frame_host/render_widget_host_view_child_frame.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 "content/browser/frame_host/render_widget_host_view_child_frame.h"
 
 #include <algorithm>
 #include <utility>
 #include <vector>
 
@@ skipping 350 matching lines @@
   CreateCompositorFrameSinkSupport();
   has_frame_ = false;
 }
 
 void RenderWidgetHostViewChildFrame::ProcessCompositorFrame(
     const cc::LocalSurfaceId& local_surface_id,
     cc::CompositorFrame frame) {
   current_surface_size_ = frame.render_pass_list.back()->output_rect.size();
   current_surface_scale_factor_ = frame.metadata.device_scale_factor;
 
-  support_->SubmitCompositorFrame(local_surface_id, std::move(frame));
+  DCHECK(support_->SubmitCompositorFrame(local_surface_id, std::move(frame)));

[danakj, 2017/05/19 19:00:59]

and here

[Saman Sami, 2017/05/19 19:26:46]

Done.

   has_frame_ = true;
 
   if (local_surface_id_ != local_surface_id || HasEmbedderChanged()) {
     local_surface_id_ = local_surface_id;
     SendSurfaceInfoToEmbedder();
   }
 
   ProcessFrameSwappedCallbacks();
 }
 
@@ skipping 342 matching lines @@
                                                       frame_sink_id_);
   }
   support_.reset();
 }
 
 bool RenderWidgetHostViewChildFrame::HasEmbedderChanged() {
   return false;
 }
 
 }  // namespace content