Convert WindowOpenDisposition to an enum class.

chrome/browser/extensions/api/web_navigation/web_navigation_api.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.
 
 // Implements the Chrome Extensions WebNavigation API.
 
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api.h"
 
 #include "base/lazy_instance.h"
 #include "chrome/browser/chrome_notification_types.h"
@@ skipping 356 matching lines @@
     content::RenderFrameHost* source_render_frame_host,
     const GURL& url,
     const content::Referrer& referrer,
     WindowOpenDisposition disposition,
     ui::PageTransition transition) {
   if (!navigation_state_.CanSendEvents(source_render_frame_host))
     return;
 
   // We only send the onCreatedNavigationTarget if we end up creating a new
   // window.
-  if (disposition != SINGLETON_TAB &&
-      disposition != NEW_FOREGROUND_TAB &&
-      disposition != NEW_BACKGROUND_TAB &&
-      disposition != NEW_POPUP &&
-      disposition != NEW_WINDOW &&
-      disposition != OFF_THE_RECORD)
+  if (disposition != WindowOpenDisposition::SINGLETON_TAB &&
+      disposition != WindowOpenDisposition::NEW_FOREGROUND_TAB &&
+      disposition != WindowOpenDisposition::NEW_BACKGROUND_TAB &&
+      disposition != WindowOpenDisposition::NEW_POPUP &&
+      disposition != WindowOpenDisposition::NEW_WINDOW &&
+      disposition != WindowOpenDisposition::OFF_THE_RECORD)
     return;
 
   helpers::DispatchOnCreatedNavigationTarget(web_contents(),
                                              new_contents->GetBrowserContext(),
                                              source_render_frame_host,
                                              new_contents,
                                              url);
 }
 
 void WebNavigationTabObserver::WebContentsDestroyed() {
@@ skipping 184 matching lines @@
   return g_factory.Pointer();
 }
 
 void WebNavigationAPI::OnListenerAdded(const EventListenerInfo& details) {
   web_navigation_event_router_.reset(new WebNavigationEventRouter(
       Profile::FromBrowserContext(browser_context_)));
   EventRouter::Get(browser_context_)->UnregisterObserver(this);
 }
 
 }  // namespace extensions