Don't use PostTask queueing between compositor and main thread.

third_party/WebKit/public/web/WebInputEvent.h

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 228 matching lines @@
     {
         return TouchTypeFirst <= type && type <= TouchTypeLast;
     }
 
     // Returns true if the WebInputEvent is a gesture event.
     static bool isGestureEventType(int type)
     {
         return GestureTypeFirst <= type && type <= GestureTypeLast;
     }
 
+    bool isSameEventClass(const WebInputEvent& other) const
+    {
+        if (isMouseEventType(type))
+            return isMouseEventType(other.type);
+        if (isGestureEventType(type))
+            return isGestureEventType(other.type);
+        if (isTouchEventType(type))
+            return isTouchEventType(other.type);
+        if (isKeyboardEventType(type))
+            return isKeyboardEventType(other.type);
+        return type == other.type;
+    }
+
 protected:
     explicit WebInputEvent(unsigned sizeParam)
     {
         memset(this, 0, sizeParam);
         timeStampSeconds = 0.0;
         size = sizeParam;
         type = Undefined;
         modifiers = 0;
     }
 };
@@ skipping 384 matching lines @@
         , uniqueTouchEventId(0)
     {
     }
 };
 
 #pragma pack(pop)
 
 } // namespace blink
 
 #endif