OverscrollGlow for mainThread-{BLINK CHANGES}

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 709 matching lines @@
         }
         // GestureDoubleTap is currently only used by Android for zooming. For WebCore,
         // GestureTap with tap count = 2 is used instead. So we drop GestureDoubleTap here.
         eventSwallowed = true;
         m_client->didHandleGestureEvent(event, eventCancelled);
         return eventSwallowed;
     case WebInputEvent::GestureScrollBegin:
         m_client->cancelScheduledContentIntents();
     case WebInputEvent::GestureScrollEnd:
     case WebInputEvent::GestureScrollUpdate:
-    case WebInputEvent::GestureFlingStart:
+    case WebInputEvent::GestureFlingStart: {
         // Scrolling-related gesture events invoke EventHandler recursively for each frame down
         // the chain, doing a single-frame hit-test per frame. This matches handleWheelEvent.
         // Perhaps we could simplify things by rewriting scroll handling to work inner frame
         // out, and then unify with other gesture events.
         eventSwallowed = mainFrameImpl()->frame()->eventHandler().handleGestureScrollEvent(platformEvent);
+        IntPoint unusedDelta = mainFrameImpl()->frame()->eventHandler().unusedDelta();
+        if (unusedDelta != IntPoint() && (event.type == WebInputEvent::GestureScrollUpdate)) {
+            IntPoint accumaltedRootOverScroll = mainFrameImpl()->frame()->eventHandler().accumaltedRootOverScroll();
+            m_client->didOverScrollOnMainThread(unusedDelta.x(), unusedDelta.y(), accumaltedRootOverScroll.x(), accumaltedRootOverScroll.y(), platformEvent.position().x(), platformEvent.position().y(), platformEvent.velocityX(), platformEvent.velocityY());
+        }

[majidvp, 2015/04/23 18:25:09]

Overscroll should be reported on both gesture and wheel scrolls.

         m_client->didHandleGestureEvent(event, eventCancelled);
         return eventSwallowed;
+    }
     case WebInputEvent::GesturePinchBegin:
     case WebInputEvent::GesturePinchEnd:
     case WebInputEvent::GesturePinchUpdate:
         return false;
     default:
         break;
     }
 
     // Hit test across all frames and do touch adjustment as necessary for the event type.
     GestureEventWithHitTestResults targetedEvent =
@@ skipping 3709 matching lines @@
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 void WebViewImpl::forceNextWebGLContextCreationToFail()
 {
     WebGLRenderingContext::forceNextWebGLContextCreationToFail();
 }
 
 } // namespace blink