Use WTF::TimeTicks to represent timestamp in Platform/Core event types

third_party/WebKit/Source/platform/PlatformGestureEvent.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 36 matching lines @@
   PlatformGestureEvent()
       : PlatformEvent(PlatformEvent::GestureScrollBegin),
         m_source(PlatformGestureSourceUninitialized) {
     memset(&m_data, 0, sizeof(m_data));
   }
 
   PlatformGestureEvent(EventType type,
                        const IntPoint& position,
                        const IntPoint& globalPosition,
                        const IntSize& area,
-                       double timestamp,
+                       TimeTicks timestamp,
                        PlatformEvent::Modifiers modifiers,
                        PlatformGestureSource source)
       : PlatformEvent(type, modifiers, timestamp),
         m_position(position),
         m_globalPosition(globalPosition),
         m_area(area),
         m_source(source) {
     memset(&m_data, 0, sizeof(m_data));
   }
 
@@ skipping 178 matching lines @@
       float m_scale;
     } m_pinchUpdate;
   } m_data;
 
   uint32_t m_uniqueTouchEventId;
 };
 
 }  // namespace blink
 
 #endif  // PlatformGestureEvent_h