Enforce constant size and device scale factor for surfaces

cc/surfaces/compositor_frame_sink_support.cc

Index: cc/surfaces/compositor_frame_sink_support.cc
diff --git a/cc/surfaces/compositor_frame_sink_support.cc b/cc/surfaces/compositor_frame_sink_support.cc
index 0fdb6c6855755951a03bcee2ce4fda161f209986..6be5dc311ae8b27dd77814482bb2fbce3f2d87ae 100644
--- a/cc/surfaces/compositor_frame_sink_support.cc
+++ b/cc/surfaces/compositor_frame_sink_support.cc
@@ -125,6 +125,21 @@ void CompositorFrameSinkSupport::SubmitCompositorFrame(
     }
   }
 
+  SurfaceId surface_id(frame_sink_id_, local_surface_id);
+  gfx::Size frame_size = frame.render_pass_list.back()->output_rect.size();
+  float device_scale_factor = frame.metadata.device_scale_factor;
+  SurfaceInfo surface_info(surface_id, device_scale_factor, frame_size);
+  if (!surface_info.is_valid()) {
+    DLOG(ERROR) << "Cannot create a surface with invalid SurfaceInfo.";

[danakj, 2017/05/18 15:15:53]

Can you make this a trace event instead so we can see it when debugging there?

[Saman Sami, 2017/05/18 20:44:37]

Done.

+    if (current_surface_)
+      DestroyCurrentSurface();
+    ReturnedResourceArray resources;
+    TransferableResource::ReturnResources(frame.resource_list, &resources);
+    ReturnResources(resources);
+    DidReceiveCompositorFrameAck();
+    return;
+  }
+
   std::unique_ptr<Surface> surface;
   bool create_new_surface =
       (!current_surface_ ||
@@ -132,7 +147,7 @@ void CompositorFrameSinkSupport::SubmitCompositorFrame(
   if (!create_new_surface) {
     surface = std::move(current_surface_);
   } else {
-    surface = CreateSurface(local_surface_id);
+    surface = CreateSurface(surface_info);
   }
 
   surface->QueueFrame(
@@ -332,10 +347,10 @@ void CompositorFrameSinkSupport::UpdateNeedsBeginFramesInternal() {
 }
 
 std::unique_ptr<Surface> CompositorFrameSinkSupport::CreateSurface(
-    const LocalSurfaceId& local_surface_id) {
+    const SurfaceInfo& surface_info) {
   seen_first_frame_activation_ = false;
-  std::unique_ptr<Surface> surface = surface_manager_->CreateSurface(
-      weak_factory_.GetWeakPtr(), local_surface_id);
+  std::unique_ptr<Surface> surface =

[danakj, 2017/05/18 15:15:54]

nit: just return here instead of using a variable

[Saman Sami, 2017/05/18 20:44:37]

Done.

+      surface_manager_->CreateSurface(weak_factory_.GetWeakPtr(), surface_info);
   return surface;
 }