Refactoring button field and its type (2nd try)

chrome/browser/unload_browsertest.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.
 
 #if defined(OS_POSIX)
 #include <signal.h>
 #endif
 
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 384 matching lines @@
   // popup will be constrained, which isn't what we want to test.
 
   content::WindowedNotificationObserver observer(
         chrome::NOTIFICATION_TAB_ADDED,
         content::NotificationService::AllSources());
   content::WindowedNotificationObserver load_stop_observer(
       content::NOTIFICATION_LOAD_STOP,
       content::NotificationService::AllSources());
   content::SimulateMouseClick(
       browser()->tab_strip_model()->GetActiveWebContents(), 0,
-      blink::WebMouseEvent::ButtonLeft);
+      blink::WebMouseEvent::Button::Left);
   observer.Wait();
   load_stop_observer.Wait();
   CheckTitle("popup");
 
   content::WebContentsDestroyedWatcher destroyed_watcher(
       browser()->tab_strip_model()->GetActiveWebContents());
   chrome::CloseTab(browser());
   destroyed_watcher.Wait();
 
   CheckTitle("only_one_unload");
@@ skipping 214 matching lines @@
   content::WindowedNotificationObserver window_observer(
         chrome::NOTIFICATION_BROWSER_CLOSED,
         content::NotificationService::AllSources());
   chrome::CloseWindow(browser());
   CrashTab(beforeunload_contents);
   window_observer.Wait();
 }
 
 // TODO(ojan): Add tests for unload/beforeunload that have multiple tabs
 // and multiple windows.