Eager Gesture Recognition on Aura

content/browser/renderer_host/render_widget_host_view_aura.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include "base/auto_reset.h"
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 1900 matching lines @@
   // 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())
+  if (host_->ShouldForwardTouchEvent()) {
+    if (point && window_->GetHost())
+      window_->GetHost()->dispatcher()->OnForwardingTouchEvent(event, window_);

[sadrul, 2014/07/16 21:07:48]

Can you explain what OnForwardingTouchEvent does, and why this is necessary?
(e.g. the code in WindowEventDispatcher::PostDispatchEvent() should be
sufficient, except it would ignore event.result())

[tdresser, 2014/07/28 18:22:09]

Moved to PreDispatchEvent.

     event->StopPropagation();
+  }
 
   if (point) {
     if (host_->ShouldForwardTouchEvent())
       host_->ForwardTouchEventWithLatencyInfo(touch_event_, *event->latency());
     UpdateWebTouchEventAfterDispatch(&touch_event_, point);
   }
 }
 
 void RenderWidgetHostViewAura::OnGestureEvent(ui::GestureEvent* event) {
   TRACE_EVENT0("input", "RenderWidgetHostViewAura::OnGestureEvent");
@@ skipping 547 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewBase, public:
 
 // static
 void RenderWidgetHostViewBase::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content