Don't pass touches to gesture recognizer for async acks.

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 49ee8e48f09e47f0b9305899e12443c993a9e26f..4fd23fe14bccdcdba248145a345a6428763ffed0 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -1140,21 +1140,38 @@ void RenderWidgetHostViewAura::GestureEventAck(
 
 void RenderWidgetHostViewAura::ProcessAckedTouchEvent(
     const TouchEventWithLatencyInfo& touch, InputEventAckState ack_result) {
-  ScopedVector<ui::TouchEvent> events;
-  if (!MakeUITouchEventsFromWebTouchEvents(touch, &events,
-                                           SCREEN_COORDINATES))
-    return;
-
   aura::WindowTreeHost* host = window_->GetHost();
-  // |host| is NULL during tests.
+  // |host| is sometimes NULL during tests.
   if (!host)
     return;
 
   ui::EventResult result = (ack_result ==
       INPUT_EVENT_ACK_STATE_CONSUMED) ? ui::ER_HANDLED : ui::ER_UNHANDLED;
-  for (ScopedVector<ui::TouchEvent>::iterator iter = events.begin(),
-      end = events.end(); iter != end; ++iter) {
-    host->dispatcher()->ProcessedTouchEvent((*iter), window_, result);
+
+  // Only send acks for changed touches.
+  blink::WebTouchPoint::State required_state;
+  switch(touch.event.type) {
+    case blink::WebInputEvent::TouchStart:
+      required_state = blink::WebTouchPoint::StatePressed;
+      break;
+    case blink::WebInputEvent::TouchEnd:
+      required_state = blink::WebTouchPoint::StateReleased;
+      break;
+    case blink::WebInputEvent::TouchMove:
+      required_state = blink::WebTouchPoint::StateMoved;
+      break;
+    case blink::WebInputEvent::TouchCancel:
+      required_state = blink::WebTouchPoint::StateCancelled;
+      break;
+    default:
+      required_state = blink::WebTouchPoint::StateUndefined;
+      DCHECK(false);

[tdresser, 2014/12/03 19:49:52]

Should be NOTREACHED().

[tdresser, 2015/02/06 17:43:49]

Done.

+      break;
+  }
+
+  for (size_t i = 0; i < touch.event.touchesLength; ++i) {
+    if (touch.event.touches[i].state == required_state)
+      host->dispatcher()->ProcessedTouchEvent(window_, result);
   }
 }