Coalesce async touch move events until the ack back from render

content/browser/renderer_host/render_widget_host_unittest.cc

Index: content/browser/renderer_host/render_widget_host_unittest.cc
diff --git a/content/browser/renderer_host/render_widget_host_unittest.cc b/content/browser/renderer_host/render_widget_host_unittest.cc
index e559b6d987833e5fa86e65407e6251f86f470f51..f980a89296206c997805c6944fcf9be515c3e6f6 100644
--- a/content/browser/renderer_host/render_widget_host_unittest.cc
+++ b/content/browser/renderer_host/render_widget_host_unittest.cc
@@ -466,9 +466,8 @@ class RenderWidgetHostTest : public testing::Test {
 
   void SendInputEventACK(WebInputEvent::Type type,
                          InputEventAckState ack_result) {
-    InputHostMsg_HandleInputEvent_ACK_Params ack;
-    ack.type = type;
-    ack.state = ack_result;
+    DCHECK(!WebInputEvent::isTouchEventType(type));
+    InputEventAck ack(type, ack_result);
     host_->OnMessageReceived(InputHostMsg_HandleInputEvent_ACK(0, ack));
   }
 
@@ -551,10 +550,12 @@ class RenderWidgetHostTest : public testing::Test {
 
   // Sends a touch event (irrespective of whether the page has a touch-event
   // handler or not).
-  void SendTouchEvent() {
+  uint32 SendTouchEvent() {
+    uint32 touch_event_id = touch_event_.uniqueTouchEventId;
     host_->ForwardTouchEventWithLatencyInfo(touch_event_, ui::LatencyInfo());
 
     touch_event_.ResetPoints();
+    return touch_event_id;
   }
 
   int PressTouchPoint(int x, int y) {
@@ -1482,10 +1483,12 @@ TEST_F(RenderWidgetHostTest, InputEventRWHLatencyComponent) {
 
   // Tests RWHI::ForwardTouchEventWithLatencyInfo().
   PressTouchPoint(0, 1);
-  SendTouchEvent();
+  uint32 touch_event_id = SendTouchEvent();
+  InputEventAck ack(WebInputEvent::TouchStart, INPUT_EVENT_ACK_STATE_CONSUMED,
+                    touch_event_id);
+  host_->OnMessageReceived(InputHostMsg_HandleInputEvent_ACK(0, ack));
   CheckLatencyInfoComponentInMessage(
       process_, GetLatencyComponentId(), WebInputEvent::TouchStart);
-  SendInputEventACK(WebInputEvent::TouchStart, INPUT_EVENT_ACK_STATE_CONSUMED);
 }
 
 TEST_F(RenderWidgetHostTest, RendererExitedResetsInputRouter) {