Make a global enum to differentiate impl & proxy.

ppapi/shared_impl/ppb_view_shared.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PPAPI_SHARED_IMPL_PPB_VIEW_SHARED_H_
 #define PPAPI_SHARED_IMPL_PPB_VIEW_SHARED_H_
 
 #include "base/compiler_specific.h"
 #include "ppapi/c/pp_rect.h"
 #include "ppapi/c/pp_size.h"
@@ skipping 13 matching lines @@
   PP_Rect rect;
   bool is_fullscreen;
   bool is_page_visible;
   PP_Rect clip_rect;
 };
 
 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();
 
   // Resource overrides.
   virtual thunk::PPB_View_API* AsPPB_View_API() OVERRIDE;
 
   // PPB_View_API implementation.
   virtual const ViewData& GetData() const OVERRIDE;
 
  private:
   ViewData data_;
 
   DISALLOW_COPY_AND_ASSIGN(PPB_View_Shared);
 };
 
 }  // namespace ppapi
 
 #endif  // PPAPI_SHARED_IMPL_PPB_VIEW_SHARED_H_