Coverity: Fix a pass-by-value.

ui/base/win/events_win.cc

 // Copyright (c) 2012 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.
 
 #include <windowsx.h>
 
 #include "ui/base/events.h"
 
 #include "base/logging.h"
 #include "base/time.h"
@@ skipping 248 matching lines @@
   // Not supported in Windows.
   *start_time = 0;
   *end_time = 0;
   return false;
 }
 
 void UpdateDeviceList() {
   NOTIMPLEMENTED();
 }
 
-bool IsNoopEvent(base::NativeEvent event) {
+bool IsNoopEvent(const base::NativeEvent& event) {
   return event.message == WM_USER + 310;
 }
 
 base::NativeEvent CreateNoopEvent() {
   MSG event = { NULL };
   event.message = WM_USER + 310;
   return event;
 }
 
 }  // namespace ui