Make a global enum to differentiate impl & proxy.

ppapi/shared_impl/ppb_input_event_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_INPUT_EVENT_SHARED_H_
 #define PPAPI_SHARED_IMPL_PPB_INPUT_EVENT_SHARED_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 37 matching lines @@
   uint32_t composition_selection_start;
   uint32_t composition_selection_end;
 };
 
 // This simple class implements the PPB_InputEvent_API in terms of the
 // shared InputEventData structure
 class PPAPI_SHARED_EXPORT PPB_InputEvent_Shared
     : public Resource,
       public thunk::PPB_InputEvent_API {
  public:
-  struct InitAsImpl {};
-  struct InitAsProxy {};
-
-  // The dummy arguments control which version of Resource's constructor is
-  // called for this base class.
-  PPB_InputEvent_Shared(const InitAsImpl&,
-                        PP_Instance instance,
-                        const InputEventData& data);
-  PPB_InputEvent_Shared(const InitAsProxy&,
+  PPB_InputEvent_Shared(ResourceObjectType type,
                         PP_Instance instance,
                         const InputEventData& data);
 
   // Resource overrides.
   virtual PPB_InputEvent_API* AsPPB_InputEvent_API() OVERRIDE;
 
   // PPB_InputEvent_API implementation.
   virtual const InputEventData& GetInputEventData() const OVERRIDE;
   virtual PP_InputEvent_Type GetType() OVERRIDE;
   virtual PP_TimeTicks GetTimeStamp() OVERRIDE;
@@ skipping 14 matching lines @@
 
  private:
   InputEventData data_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PPB_InputEvent_Shared);
 };
 
 }  // namespace ppapi
 
 #endif  // PPAPI_SHARED_IMPL_PPB_INPUT_EVENT_SHARED_H_