Add GetScrollOffset function to PPB_View

ppapi/thunk/ppb_view_api.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_THUNK_PPB_VIEW_API_H_
 #define PPAPI_THUNK_PPB_VIEW_API_H_
 
 #include "ppapi/thunk/ppapi_thunk_export.h"
 
 namespace ppapi {
 
 struct ViewData;
 
 namespace thunk {
 
 class PPAPI_THUNK_EXPORT PPB_View_API {
  public:
   virtual ~PPB_View_API() {}
 
   // Returns the view data struct.
   virtual const ViewData& GetData() const = 0;
 
   virtual PP_Bool GetRect(PP_Rect* viewport) const = 0;
   virtual PP_Bool IsFullscreen() const = 0;
   virtual PP_Bool IsVisible() const = 0;
   virtual PP_Bool IsPageVisible() const = 0;
   virtual PP_Bool GetClipRect(PP_Rect* clip) const = 0;
   virtual float GetDeviceScale() const = 0;
   virtual float GetCSSScale() const = 0;
+  virtual PP_Bool GetScrollOffset(PP_Point* offset) const = 0;
 };
 
 }  // namespace thunk
 }  // namespace ppapi
 
 #endif // PPAPI_THUNK_PPB_VIEW_API_H_