Replace usage of SurfaceId's client_id with FrameSinkId

blimp/client/support/compositor/compositor_dependencies_impl.cc

Index: blimp/client/support/compositor/compositor_dependencies_impl.cc
diff --git a/blimp/client/support/compositor/compositor_dependencies_impl.cc b/blimp/client/support/compositor/compositor_dependencies_impl.cc
index 4b0fdce1fbf1fb7aa10ad6a6256c75682f685988..b85aad9c4baabc0c752ce085e6b497f3616cea12 100644
--- a/blimp/client/support/compositor/compositor_dependencies_impl.cc
+++ b/blimp/client/support/compositor/compositor_dependencies_impl.cc
@@ -31,8 +31,8 @@ cc::SurfaceManager* CompositorDependenciesImpl::GetSurfaceManager() {
   return surface_manager_.get();
 }
 
-uint32_t CompositorDependenciesImpl::AllocateSurfaceClientId() {
-  return ++next_surface_id_;
+cc::FrameSinkId CompositorDependenciesImpl::AllocateFrameSinkId() {
+  return cc::FrameSinkId(++next_surface_id_, 0 /* sink_id */);
 }
 
 void CompositorDependenciesImpl::GetContextProviders(