gestures: Generate only either scroll-end or fling-start events at the end of a scroll gesture.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 273907861e0e07d693f87371bafabddd2f27a41e..0fe503fe45ba1c06811187aae432a81cc0521204 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -1318,6 +1318,11 @@ ui::GestureStatus RenderWidgetHostViewAura::OnGestureEvent(
     WebKit::WebGestureEvent fling_cancel = gesture;
     fling_cancel.type = WebKit::WebInputEvent::GestureFlingCancel;
     host_->ForwardGestureEvent(fling_cancel);
+  } else if (event->type() == ui::ET_SCROLL_FLING_START) {
+    // WebKit requires that a scroll ends first before a fling starts.

[rjkroege, 2012/08/09 16:51:06]

It is planned to remove this requirement on WebKit. Did you test without the
presence of this code? It is my intent that this ought to be removed from here
if it is currently necessary.

[sadrul, 2012/08/09 17:44:02]

Nice! My impression was that it was still necessary. But I tried without this
block of code, in debug and release builds on desktop, and on device, and scroll
with/without fling seems to work fine. So I have removed this change. Thanks!

+    WebKit::WebGestureEvent scroll_end = gesture;
+    gesture.type = WebKit::WebInputEvent::GestureScrollEnd;
+    host_->ForwardGestureEvent(scroll_end);
   }
 
   if (gesture.type != WebKit::WebInputEvent::Undefined) {