WIP: Propagate SurfaceID up window tree hierarchy

ui/views/mus/surface_context_factory.cc

Index: ui/views/mus/surface_context_factory.cc
diff --git a/ui/views/mus/surface_context_factory.cc b/ui/views/mus/surface_context_factory.cc
index 5ddc564d36efaaef1bc84b9d2fbacc7926accc97..330791e73904612db58cbd9221a4677a1122cb12 100644
--- a/ui/views/mus/surface_context_factory.cc
+++ b/ui/views/mus/surface_context_factory.cc
@@ -29,7 +29,9 @@ class FakeReflector : public ui::Reflector {
 }  // namespace
 
 SurfaceContextFactory::SurfaceContextFactory(ui::GpuService* gpu_service)
-    : next_surface_id_namespace_(1u), gpu_service_(gpu_service) {}
+    : surface_manager_(nullptr),
+      next_surface_id_namespace_(1u),
+      gpu_service_(gpu_service) {}
 
 SurfaceContextFactory::~SurfaceContextFactory() {}
 
@@ -89,8 +91,8 @@ cc::TaskGraphRunner* SurfaceContextFactory::GetTaskGraphRunner() {
   return raster_thread_helper_.task_graph_runner();
 }
 
-uint32_t SurfaceContextFactory::AllocateSurfaceClientId() {
-  return next_surface_id_namespace_++;
+cc::FrameSinkId SurfaceContextFactory::AllocateFrameSinkId() {
+  return cc::FrameSinkId(next_surface_id_namespace_++, 0);
 }
 
 cc::SurfaceManager* SurfaceContextFactory::GetSurfaceManager() {