Make a global enum to differentiate impl & proxy.

ppapi/shared_impl/ppb_view_shared.h

Index: ppapi/shared_impl/ppb_view_shared.h
diff --git a/ppapi/shared_impl/ppb_view_shared.h b/ppapi/shared_impl/ppb_view_shared.h
index ecfb1a0d124278bb4e27f9ed68c15230f0eacdfa..13074075a44f4a426133eadda7e12db40ccc4f2a 100644
--- a/ppapi/shared_impl/ppb_view_shared.h
+++ b/ppapi/shared_impl/ppb_view_shared.h
@@ -31,15 +31,7 @@ class PPAPI_SHARED_EXPORT PPB_View_Shared
     : public Resource,
       public thunk::PPB_View_API {
  public:
-  struct InitAsImpl {};
-  struct InitAsProxy {};
-
-  // The dummy arguments control which version of Resource's constructor is
-  // called for this base class.
-  PPB_View_Shared(const InitAsImpl&,
-                  PP_Instance instance,
-                  const ViewData& data);
-  PPB_View_Shared(const InitAsProxy&,
+  PPB_View_Shared(ResourceObjectType type,
                   PP_Instance instance,
                   const ViewData& data);
   virtual ~PPB_View_Shared();