Send input event's LatencyInfo back from renderer to browser when acked

content/common/input_messages.h

 // Copyright (c) 2013 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.
 
 // IPC messages for input events and other messages that require processing in
 // order relative to input events.
 // Multiply-included message file, hence no include guard.
 
 #include "base/strings/string16.h"
 #include "content/common/content_export.h"
@@ skipping 108 matching lines @@
 IPC_MESSAGE_ROUTED3(InputMsg_ActivateNearestFindResult,
                     int /* request_id */,
                     float /* x */,
                     float /* y */)
 #endif
 
 // -----------------------------------------------------------------------------
 // Messages sent from the renderer to the browser.
 
 // Acknowledges receipt of a InputMsg_HandleInputEvent message.
-IPC_MESSAGE_ROUTED2(InputHostMsg_HandleInputEvent_ACK,
+IPC_MESSAGE_ROUTED3(InputHostMsg_HandleInputEvent_ACK,
                     WebKit::WebInputEvent::Type,
-                    content::InputEventAckState /* ack_result */)
+                    content::InputEventAckState /* ack_result */,
+                    ui::LatencyInfo /* latency_info */)
 
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent InputMsg, then ifdefs for platform specific InputMsg, then
 // platform independent InputHostMsg, then ifdefs for platform specific
 // InputHostMsg.