Split surface id and simplify connecting to surfaces service

sky/compositor/surface_holder.cc

Index: sky/compositor/surface_holder.cc
diff --git a/sky/compositor/surface_holder.cc b/sky/compositor/surface_holder.cc
index 26d2098c96061ef918b92ce79ed37c54a5247e2d..e8475802f301a0fecba33f20a8c06b8f3e6534fb 100644
--- a/sky/compositor/surface_holder.cc
+++ b/sky/compositor/surface_holder.cc
@@ -51,13 +51,16 @@ void SurfaceHolder::SetSize(const gfx::Size& size) {
     surface_id_ = mojo::SurfaceId::New();
   }
 
-  surface_id_->id = surface_allocator_->CreateSurfaceId();
-  surface_->CreateSurface(surface_id_.Clone(), mojo::Size::From(size));
+  surface_id_ = surface_allocator_->CreateSurfaceId();
+  surface_->CreateSurface(surface_id_.Clone());
   size_ = size;
 
   client_->OnSurfaceIdAvailable(surface_id_.Clone());
 }
 
+void SurfaceHolder::SetIdNamespace(uint32_t id_namespace) {
+}
+
 void SurfaceHolder::ReturnResources(
     mojo::Array<mojo::ReturnedResourcePtr> resources) {
   // TODO(abarth): The surface service shouldn't spam us with empty calls.