Fix dcheck failing on ChromeOS

third_party/WebKit/Source/core/input/ScrollManager.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/input/ScrollManager.h"
 
 #include <memory>
 #include "core/dom/DOMNodeIds.h"
 #include "core/events/GestureEvent.h"
 #include "core/frame/BrowserControls.h"
@@ skipping 443 matching lines @@
   }
 
   switch (gestureEvent.type()) {
     case WebInputEvent::GestureScrollBegin:
       return handleGestureScrollBegin(gestureEvent);
     case WebInputEvent::GestureScrollUpdate:
       return handleGestureScrollUpdate(gestureEvent);
     case WebInputEvent::GestureScrollEnd:
       return handleGestureScrollEnd(gestureEvent);
     case WebInputEvent::GestureFlingStart:
+    case WebInputEvent::GestureFlingCancel:
     case WebInputEvent::GesturePinchBegin:
     case WebInputEvent::GesturePinchEnd:
     case WebInputEvent::GesturePinchUpdate:
       return WebInputEventResult::NotHandled;
     default:
       NOTREACHED();
       return WebInputEventResult::NotHandled;
   }
 }
 
@@ skipping 79 matching lines @@
     if (scrollbar->gestureEvent(targetedEvent.event(), &shouldUpdateCapture)) {
       if (shouldUpdateCapture)
         m_scrollbarHandlingScrollGesture = scrollbar;
       return true;
     }
   }
   return false;
 }
 
 }  // namespace blink