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 @@
     case WebInputEvent::GestureScrollBegin:
         m_client->cancelScheduledContentIntents();
     case WebInputEvent::GestureScrollEnd:
     case WebInputEvent::GestureScrollUpdate:
     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);
+        {
+            FloatPoint unusedDelta = mainFrameImpl()->frame()->eventHandler().unusedDelta();
+            if (unusedDelta != FloatPoint() && (event.type == WebInputEvent::GestureScrollUpdate)) {
+                FloatPoint accumaltedRootOverScroll = mainFrameImpl()->frame()->eventHandler().accumulatedRootOverScroll();
+                m_client->didOverScrollOnMainThread(unusedDelta.x(), unusedDelta.y(), accumaltedRootOverScroll.x(), accumaltedRootOverScroll.y(), platformEvent.position().x(), platformEvent.position().y(), platformEvent.velocityX(), platformEvent.velocityY());

[aelias_OOO_until_Jul13, 2015/05/01 04:45:04]

Can this be called directly from handleGestureScrollUpdate, so that the logic
isn't split across two gesture handling methods and shared implicitly using
member variables?  (It's fine if it needs to pass through a new WebViewImpl
plumbing method to do that.)

[MuVen, 2015/05/04 09:04:18]

Done.

+            }
+        }
         m_client->didHandleGestureEvent(event, eventCancelled);
         return eventSwallowed;
     case WebInputEvent::GesturePinchBegin:
     case WebInputEvent::GesturePinchEnd:
     case WebInputEvent::GesturePinchUpdate:
         return false;
     default:
         break;
     }
 
@@ skipping 3727 matching lines @@
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 void WebViewImpl::forceNextWebGLContextCreationToFail()
 {
     WebGLRenderingContext::forceNextWebGLContextCreationToFail();
 }
 
 } // namespace blink