Set the unique_event_id when converting from TouchEvent to WebTouchEvent

content/browser/renderer_host/input/input_router_impl.cc

Index: content/browser/renderer_host/input/input_router_impl.cc
diff --git a/content/browser/renderer_host/input/input_router_impl.cc b/content/browser/renderer_host/input/input_router_impl.cc
index 54bf892014c80b6884e624cdcdaac312c0817e46..7edf1d6f203c767ff6831c47839245e2b8c1d491 100644
--- a/content/browser/renderer_host/input/input_router_impl.cc
+++ b/content/browser/renderer_host/input/input_router_impl.cc
@@ -347,8 +347,10 @@ void InputRouterImpl::OfferToHandlers(const WebInputEvent& input_event,
   // Touch events should always indicate in the event whether they are
   // cancelable (respect ACK disposition) or not.
   bool ignores_ack = WebInputEventTraits::IgnoresAckDisposition(input_event);
+  uint64 unique_touch_event_id = 0;
   if (WebInputEvent::isTouchEventType(input_event.type)) {
     const WebTouchEvent& touch = static_cast<const WebTouchEvent&>(input_event);
+    unique_touch_event_id = touch.uniqueTouchEventId;
     DCHECK_NE(ignores_ack, !!touch.cancelable);
   }
 
@@ -357,6 +359,7 @@ void InputRouterImpl::OfferToHandlers(const WebInputEvent& input_event,
     ProcessInputEventAck(input_event.type,
                          INPUT_EVENT_ACK_STATE_IGNORED,
                          latency_info,
+                         unique_touch_event_id,
                          IGNORING_DISPOSITION);
   }
 }
@@ -364,6 +367,7 @@ void InputRouterImpl::OfferToHandlers(const WebInputEvent& input_event,
 bool InputRouterImpl::OfferToClient(const WebInputEvent& input_event,
                                     const ui::LatencyInfo& latency_info) {
   bool consumed = false;
+  uint64 unique_touch_event_id = 0;
 
   InputEventAckState filter_ack =
       client_->FilterInputEvent(input_event, latency_info);
@@ -372,7 +376,13 @@ bool InputRouterImpl::OfferToClient(const WebInputEvent& input_event,
     case INPUT_EVENT_ACK_STATE_NO_CONSUMER_EXISTS:
       // Send the ACK and early exit.
       next_mouse_move_.reset();
-      ProcessInputEventAck(input_event.type, filter_ack, latency_info, CLIENT);
+      if (WebInputEvent::isTouchEventType(input_event.type)) {
+        const WebTouchEvent& touch =
+            static_cast<const WebTouchEvent&>(input_event);
+        unique_touch_event_id = touch.uniqueTouchEventId;
+      }
+      ProcessInputEventAck(input_event.type, filter_ack, latency_info,
+          unique_touch_event_id, CLIENT);
       // WARNING: |this| may be deleted at this point.
       consumed = true;
       break;
@@ -417,8 +427,8 @@ void InputRouterImpl::OnInputEventAck(
            ack.type == WebInputEvent::GestureScrollUpdate);
     OnDidOverscroll(*ack.overscroll);
   }
-
-  ProcessInputEventAck(ack.type, ack.state, ack.latency, RENDERER);
+  ProcessInputEventAck(ack.type, ack.state, ack.latency,
+      ack.unique_touch_event_id, RENDERER);
   // WARNING: |this| may be deleted at this point.
 
   // This is used only for testing, and the other end does not use the
@@ -489,6 +499,7 @@ void InputRouterImpl::ProcessInputEventAck(
     WebInputEvent::Type event_type,
     InputEventAckState ack_result,
     const ui::LatencyInfo& latency_info,
+    uint64 uniqueEventId,
     AckSource ack_source) {
   TRACE_EVENT2("input", "InputRouterImpl::ProcessInputEventAck",
                "type", WebInputEventTraits::GetName(event_type),
@@ -511,7 +522,8 @@ void InputRouterImpl::ProcessInputEventAck(
   } else if (event_type == WebInputEvent::MouseWheel) {
     ProcessWheelAck(ack_result, latency_info);
   } else if (WebInputEvent::isTouchEventType(event_type)) {
-    ProcessTouchAck(ack_result, latency_info);
+    DCHECK_NE(uniqueEventId, 0UL);
+    ProcessTouchAck(ack_result, latency_info, uniqueEventId);
   } else if (WebInputEvent::isGestureEventType(event_type)) {
     ProcessGestureAck(event_type, ack_result, latency_info);
   } else if (event_type != WebInputEvent::Undefined) {
@@ -592,9 +604,11 @@ void InputRouterImpl::ProcessGestureAck(WebInputEvent::Type type,
 
 void InputRouterImpl::ProcessTouchAck(
     InputEventAckState ack_result,
-    const ui::LatencyInfo& latency) {
+    const ui::LatencyInfo& latency,
+    uint64 unique_touch_event_id) {
   // |touch_event_queue_| will forward to OnTouchEventAck when appropriate.
-  touch_event_queue_.ProcessTouchAck(ack_result, latency);
+  touch_event_queue_.ProcessTouchAck(ack_result, latency,
+      unique_touch_event_id);
 }
 
 void InputRouterImpl::UpdateTouchAckTimeoutEnabled() {