Aura-Mus: Allocate a LocalSurfaceId on size change

ui/aura/mus/window_port_mus.h

Index: ui/aura/mus/window_port_mus.h
diff --git a/ui/aura/mus/window_port_mus.h b/ui/aura/mus/window_port_mus.h
index f708296435e4ea60ee4b746acc3061c06964ce9c..0e58a2948f30e548aa6db6a7760e5a5f51b761ff 100644
--- a/ui/aura/mus/window_port_mus.h
+++ b/ui/aura/mus/window_port_mus.h
@@ -219,6 +219,9 @@ class AURA_EXPORT WindowPortMus : public WindowPort, public WindowMus {
       const std::string& property_name,
       const std::vector<uint8_t>* property_data) override;
   void SetFrameSinkIdFromServer(const cc::FrameSinkId& frame_sink_id) override;
+  const cc::LocalSurfaceId& GetLocalSurfaceId() override;
+  const cc::LocalSurfaceId& GetOrAllocateLocalSurfaceId(
+      const gfx::Size& surface_size) override;
   void SetSurfaceInfoFromServer(const cc::SurfaceInfo& surface_info) override;
   void DestroyFromServer() override;
   void AddTransientChildFromServer(WindowMus* child) override;
@@ -264,6 +267,10 @@ class AURA_EXPORT WindowPortMus : public WindowPort, public WindowMus {
 
   cc::SurfaceInfo surface_info_;
 
+  cc::LocalSurfaceId local_surface_id_;
+  cc::LocalSurfaceIdAllocator local_surface_id_allocator_;
+  gfx::Size last_surface_size_;
+
   ui::mojom::Cursor predefined_cursor_ = ui::mojom::Cursor::CURSOR_NULL;
 
   DISALLOW_COPY_AND_ASSIGN(WindowPortMus);