Pepper and WebKit API change to support a plugin knowing if a scrollbar is an overlay one.

ppapi/cpp/dev/widget_client_dev.h

 // Copyright (c) 2010 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_CPP_DEV_WIDGET_CLIENT_DEV_H_
 #define PPAPI_CPP_DEV_WIDGET_CLIENT_DEV_H_
 
 #include "ppapi/c/pp_stdint.h"
 
 namespace pp {
@@ skipping 17 matching lines @@
    */
   virtual void InvalidateWidget(Widget_Dev widget, const Rect& dirty_rect) = 0;
 
   /**
    * Notification that the given scrollbar should change value. This is the
    * implementation for PPP_Scrollbar_Dev.
    */
   virtual void ScrollbarValueChanged(Scrollbar_Dev scrollbar,
                                      uint32_t value) = 0;
 
+  /**
+   * Notification that the given scrollbar's overlay type has changed. This is
+   * the implementation for PPP_Scrollbar_Dev.
+   */
+  virtual void ScrollbarOverlayChanged(Scrollbar_Dev scrollbar,
+                                       bool type) = 0;
+
  private:
   Instance* associated_instance_;
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_DEV_WIDGET_CLIENT_DEV_H_