Re-enable Eager Gesture Recognition on Aura

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 0cfdf26add55f9f86d5db2bb9900ea2fbcdfabef..52afd71777dcf5b52b8f40d37339fa2419f3c39f 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -2033,23 +2033,30 @@ void RenderWidgetHostViewAura::OnTouchEvent(ui::TouchEvent* event) {
     return;
 
   // Update the touch event first.
-  blink::WebTouchPoint* point = UpdateWebTouchEventFromUIEvent(*event,
-                                                                &touch_event_);
-
-  // Forward the touch event only if a touch point was updated, and there's a
-  // touch-event handler in the page, and no other touch-event is in the queue.
-  // It is important to always consume the event if there is a touch-event
-  // handler in the page, or some touch-event is already in the queue, even if
-  // no point has been updated, to make sure that this event does not get
-  // processed by the gesture recognizer before the events in the queue.
-  if (host_->ShouldForwardTouchEvent())
-    event->StopPropagation();
+  blink::WebTouchPoint* point =
+      UpdateWebTouchEventFromUIEvent(*event, &touch_event_);
+
+  if (!point) {
+    event->DisableSynchronousHandling();

[jdduke (slow), 2014/11/25 20:26:36]

Does this behave differently than just marking the event as handled and early
returning?

[tdresser, 2014/11/26 15:17:18]

We need to distinguish between the case where an event is being handled
asynchronously, and the case where an event has been consumed for some other
reason.

WindowEventDispatcher::PostDispatchEvent will ignore the event if its already
being handled async, but needs to pass the event to the GR if it's been consumed
for some other reason.

[tdresser, 2014/11/28 18:33:37]

Oh, you're right.
I do still need that flag, but I don't need to use it here.

Good catch.

+    // Mark the most recent touch event as handled, as it wasn't valid.
+    ui::GestureRecognizer::Get()->AckSyncTouchEvent(*event, ui::ER_HANDLED,
+                                                    window_);
+    return;
+  }
 
-  if (point) {
-    if (host_->ShouldForwardTouchEvent())
-      host_->ForwardTouchEventWithLatencyInfo(touch_event_, *event->latency());
-    UpdateWebTouchEventAfterDispatch(&touch_event_, point);
+  // Forward the touch event only if a touch point was updated, and
+  // there's a touch-event handler in the page, and no other
+  // touch-event is in the queue. It is important to always mark
+  // events as being handled asynchronously if there is a touch-event
+  // handler in the page, or some touch-event is already in the queue,
+  // even if no point has been updated. This ensures that this event
+  // does not get processed by the gesture recognizer before events
+  // currently awaiting dispatch in the touch queue.
+  if (host_->ShouldForwardTouchEvent()) {
+    event->DisableSynchronousHandling();
+    host_->ForwardTouchEventWithLatencyInfo(touch_event_, *event->latency());
   }
+  UpdateWebTouchEventAfterDispatch(&touch_event_, point);
 }
 
 void RenderWidgetHostViewAura::OnGestureEvent(ui::GestureEvent* event) {