Modify gesture event types for WebView-tag scroll bubbling.

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 1d3f446d1e4acd57d7eb6a03c54d22d081d766d6..6c78d5944638688c61ad09dbc5bffcd7b2e4ac6e 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -687,6 +687,7 @@ bool WebViewImpl::handleGestureEvent(const WebGestureEvent& event)
     if (!m_client)
         return false;
 
+

[tdresser, 2015/09/15 13:13:08]

Remove space.

[wjmaclean, 2015/09/15 15:02:48]

Done.

     bool eventSwallowed = false;
     bool eventCancelled = false; // for disambiguation
 
@@ -707,6 +708,12 @@ bool WebViewImpl::handleGestureEvent(const WebGestureEvent& event)
         scheduleAnimation();
         eventSwallowed = true;
 
+        // Plugins may need to see GestureFlingStart to balance
+        // GestureScrollBegin (since the former replaces GestureScrollEnd when
+        // transitioning to a fling).
+        PlatformGestureEventBuilder platformEvent(mainFrameImpl()->frameView(), event);
+        mainFrameImpl()->frame()->eventHandler().handleGestureScrollEvent(platformEvent);

[tdresser, 2015/09/15 13:13:08]

Why do we need to explicitly repost the fling? Can it take the same path that
other gestures are taking?

[wjmaclean, 2015/09/15 15:02:48]

No, the GestureFlingStart gets dropped on the floor in EventHandler. Even in
this pathway, doesn't the eventSwallowed = true mean it never propagates past
this point?

[tdresser, 2015/09/15 15:28:29]

I wonder if by not swallowing the event we could avoid having to explicitly
repost. I'm not certain either way, but it might be worth trying.

+
         m_client->didHandleGestureEvent(event, eventCancelled);
         return eventSwallowed;
     }
@@ -1864,7 +1871,7 @@ void WebViewImpl::beginFrame(const WebBeginFrameArgs& frameTime)
             PlatformGestureEvent endScrollEvent(PlatformEvent::GestureScrollEnd,
                 m_positionOnFlingStart, m_globalPositionOnFlingStart,
                 IntSize(), 0, false, false, false, false);
-            endScrollEvent.setScrollGestureData(0, 0, 0, 0, true, false);
+            endScrollEvent.setScrollGestureData(0, 0, 0, 0, true, false, 0);

[tdresser, 2015/09/15 13:13:08]

-1

We might want to define a constant for this, indicating that this means that the
event is not reposted.

[wjmaclean, 2015/09/15 15:02:48]

Done.

 
             mainFrameImpl()->frame()->eventHandler().handleGestureScrollEnd(endScrollEvent);
         }