Coalesce async touch move events until the ack back from render

content/browser/renderer_host/render_widget_host_view_aura_unittest.cc

Index: content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc b/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
index aba2b57322ef07d0fe0960cff38befe6ac9c07b5..949e7210975a86ac029b649038df1fa270f66031 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
@@ -446,6 +446,8 @@ class RenderWidgetHostViewAuraTest : public testing::Test {
     InputHostMsg_HandleInputEvent_ACK_Params ack;
     ack.type = type;
     ack.state = ack_result;
+    if (WebInputEvent::isTouchEventType(type))
+      ack.unique_touch_event_id = last_send_event_id_;
     InputHostMsg_HandleInputEvent_ACK response(0, ack);
     widget_host_->OnMessageReceived(response);
   }
@@ -466,12 +468,14 @@ class RenderWidgetHostViewAuraTest : public testing::Test {
       return;
     }
 
-    if (WebInputEventTraits::IgnoresAckDisposition(*get<0>(params)))
+    if (!WebInputEventTraits::WillReceiveAckFromRenderer(*get<0>(params)))
       return;
 
     SendInputEventACK(get<0>(params)->type, ack_result);
   }
 
+  void SetLastSentEventID(uint32 event_id) { last_send_event_id_ = event_id; }
+
  protected:
   // If true, then calls RWH::Shutdown() instead of deleting RWH.
   bool widget_host_uses_shutdown_to_destroy_;
@@ -497,6 +501,8 @@ class RenderWidgetHostViewAuraTest : public testing::Test {
 
   IPC::TestSink* sink_;
 
+  uint32 last_send_event_id_;

[jdduke (slow), 2015/05/01 19:11:09]

Nit: last_sent

[lanwei, 2015/05/07 04:11:37]

Done.

+
  private:
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewAuraTest);
 };
@@ -699,6 +705,7 @@ class RenderWidgetHostViewAuraOverscrollTest
   void SendTouchEvent() {
     widget_host_->ForwardTouchEventWithLatencyInfo(touch_event_,
                                                    ui::LatencyInfo());
+    last_send_event_id_ = touch_event_.uniqueTouchEventId;

[jdduke (slow), 2015/05/01 19:11:09]

Hmm, but what if touches are still in the queue? Or do we not test that? This
method gets called *before* a touch is sent to the queue, so if we then ack an
event that has already been sent, we're acking the wrong event.

     touch_event_.ResetPoints();
   }
 
@@ -3312,12 +3319,14 @@ TEST_F(RenderWidgetHostViewAuraTest, CorrectNumberOfAcksAreDispatched) {
       ui::ET_TOUCH_PRESSED, gfx::Point(30, 30), 0, ui::EventTimeForNow());
 
   view_->OnTouchEvent(&press1);
+  SetLastSentEventID(press1.unique_event_id());
   SendInputEventACK(blink::WebInputEvent::TouchStart,
                     INPUT_EVENT_ACK_STATE_CONSUMED);
 
   ui::TouchEvent press2(
       ui::ET_TOUCH_PRESSED, gfx::Point(20, 20), 1, ui::EventTimeForNow());
   view_->OnTouchEvent(&press2);
+  SetLastSentEventID(press2.unique_event_id());
   SendInputEventACK(blink::WebInputEvent::TouchStart,
                     INPUT_EVENT_ACK_STATE_CONSUMED);