Notify Blink about start of gesture scroll through a queued event.

third_party/WebKit/Source/platform/PlatformEvent.h

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 56 matching lines @@
         GesturePinchBegin,
         GesturePinchEnd,
         GesturePinchUpdate,
         GestureFlingStart,
 
         // PlatformTouchEvent
         TouchStart,
         TouchMove,
         TouchEnd,
         TouchCancel,
+        TouchScrollStarted,
     };
 
     // These values are direct mappings of the values in WebInputEvent so the values can be cast between the
     // enumerations. static_asserts checking this are in web/WebInputEventConversion.cpp.
     enum Modifiers {
         NoModifiers = 0,
         ShiftKey    = 1 << 0,
         CtrlKey     = 1 << 1,
         AltKey      = 1 << 2,
         MetaKey     = 1 << 3,
@@ skipping 74 matching lines @@
     }
 
     unsigned m_type;
     unsigned m_modifiers;
     double m_timestamp;
 };
 
 } // namespace blink
 
 #endif // PlatformEvent_h