Remove canScroll from WebMouseWheelEvent as it is unused now.

third_party/WebKit/Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 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 931 matching lines @@
     //  - magnitude roughly matches wheels: f(2) > 25 && f(2) < 100
     //  - a formula that's relatively easy to use from JavaScript
     // Note that 'wheel' event deltaY values have their sign inverted.  So to
     // convert a wheel deltaY back to a scale use Math.exp(-deltaY/100).
     DCHECK_GT(pinchEvent.data.pinchUpdate.scale, 0);
     wheelEvent.deltaY = 100.0f * log(pinchEvent.data.pinchUpdate.scale);
     wheelEvent.hasPreciseScrollingDeltas = true;
     wheelEvent.wheelTicksX = 0;
     wheelEvent.wheelTicksY =
         pinchEvent.data.pinchUpdate.scale > 1 ? 1 : -1;
-    wheelEvent.canScroll = false;
 
     return handleInputEvent(wheelEvent);
 }
 
 void WebViewImpl::transferActiveWheelFlingAnimation(const WebActiveWheelFlingParameters& parameters)
 {
     TRACE_EVENT0("blink", "WebViewImpl::transferActiveWheelFlingAnimation");
     DCHECK(!m_gestureAnimation);
     m_positionOnFlingStart = parameters.point;
     m_globalPositionOnFlingStart = parameters.globalPoint;
@@ skipping 3601 matching lines @@
 {
     // TODO(oshima): Investigate if this should return the ScreenInfo's scale factor rather than
     // page's scale factor, which can be 1 in use-zoom-for-dsf mode.
     if (!page())
         return 1;
 
     return page()->deviceScaleFactor();
 }
 
 } // namespace blink