Update Surface ID Terminology

services/ui/surfaces/surfaces_state.h

Index: services/ui/surfaces/surfaces_state.h
diff --git a/services/ui/surfaces/surfaces_state.h b/services/ui/surfaces/surfaces_state.h
index c55fb08142e012de47283430ceb0175710a9c3cd..c35f9005ab3a4c17c37b4806423ce7f0fbbcf024 100644
--- a/services/ui/surfaces/surfaces_state.h
+++ b/services/ui/surfaces/surfaces_state.h
@@ -27,7 +27,7 @@ class SurfacesState : public base::RefCounted<SurfacesState> {
  public:
   SurfacesState();
 
-  uint32_t next_id_namespace() { return next_id_namespace_++; }
+  uint32_t next_client_id() { return next_client_id_++; }
 
   cc::SurfaceManager* manager() { return &manager_; }
 
@@ -38,7 +38,7 @@ class SurfacesState : public base::RefCounted<SurfacesState> {
   // A Surface ID is an unsigned 64-bit int where the high 32-bits are generated
   // by the Surfaces service, and the low 32-bits are generated by the process
   // that requested the Surface.
-  uint32_t next_id_namespace_;
+  uint32_t next_client_id_;
   cc::SurfaceManager manager_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfacesState);