Make first TouchStart and first TouchMove events on a flinging layer non-blocking

third_party/WebKit/public/platform/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 184 matching lines @@
     // so the values can be cast between the enumerations. static_asserts
     // checking this are in web/WebInputEventConversion.cpp.
     enum DispatchType {
         // Event can be canceled.
         Blocking,
         // Event can not be canceled.
         EventNonBlocking,
         // All listeners are passive; not cancelable.
         ListenersNonBlockingPassive,
         // This value represents a state which would have normally blocking
-        // but was forced to be non-blocking; not cancelable.
-        ListenersForcedNonBlockingPassive,
+        // but was forced to be non-blocking during fling; not cancelable.
+        ListenersForcedNonBlockingDueToFling,
     };
 
     // The rail mode for a wheel event specifies the axis on which scrolling is
     // expected to stick. If this axis is set to Free, then scrolling is not
     // stuck to any axis.
     enum RailsMode {
         RailsModeFree       = 0,
         RailsModeHorizontal = 1,
         RailsModeVertical   = 2,
     };
@@ skipping 400 matching lines @@
 
     // For a single touch, this is true after the touch-point has moved beyond
     // the platform slop region. For a multitouch, this is true after any
     // touch-point has moved (by whatever amount).
     bool movedBeyondSlopRegion;
 
     // Whether there was an active fling animation when the event was
     // dispatched.
     bool dispatchedDuringFling;
 
+    // Whether this touch event is a touchstart or a first touchmove event per scroll.
+    bool touchStartOrFirstTouchMove;
+
     // A unique identifier for the touch event. Valid ids start at one and
     // increase monotonically. Zero means an unknown id.
     uint32_t uniqueTouchEventId;
 
     WebTouchEvent()
         : WebInputEvent(sizeof(WebTouchEvent))
         , touchesLength(0)
         , dispatchType(Blocking)
         , movedBeyondSlopRegion(false)
         , dispatchedDuringFling(false)
+        , touchStartOrFirstTouchMove(false)
         , uniqueTouchEventId(0)
     {
     }
 };
 
 #pragma pack(pop)
 
 } // namespace blink
 
 #endif