InitEvent should not do anything if dispatch flag is set.

third_party/WebKit/Source/modules/device_orientation/DeviceMotionEvent.cpp

 /*
  * Copyright (C) 2010 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 30 matching lines @@
 }
 
 DeviceMotionEvent::DeviceMotionEvent(const AtomicString& eventType, DeviceMotionData* deviceMotionData)
     : Event(eventType, false, false) // Can't bubble, not cancelable
     , m_deviceMotionData(deviceMotionData)
 {
 }
 
 void DeviceMotionEvent::initDeviceMotionEvent(const AtomicString& type, bool bubbles, bool cancelable, DeviceMotionData* deviceMotionData)
 {
-    if (dispatched())
+    if (isBeingDispatched())
         return;
 
     initEvent(type, bubbles, cancelable);
     m_deviceMotionData = deviceMotionData;
 
     m_acceleration.clear();
     m_accelerationIncludingGravity.clear();
     m_rotationRate.clear();
 }
 
@@ skipping 47 matching lines @@
 DEFINE_TRACE(DeviceMotionEvent)
 {
     visitor->trace(m_deviceMotionData);
     visitor->trace(m_acceleration);
     visitor->trace(m_accelerationIncludingGravity);
     visitor->trace(m_rotationRate);
     Event::trace(visitor);
 }
 
 } // namespace blink