Convert WindowOpenDisposition to an enum class.

chrome/browser/ui/cocoa/browser_window_controller_browsertest.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 
 #include <stddef.h>
 #import "base/mac/mac_util.h"
 
 #include "base/mac/sdk_forward_declarations.h"
@@ skipping 428 matching lines @@
   // are false.
   void VerifyFullscreenResizeFlagsAfterTransition() {
     ASSERT_FALSE([controller() isLayoutSubviewsBlocked]);
     ASSERT_FALSE([controller() isActiveTabContentsControllerResizeBlocked]);
   }
 
   // Inserts a new tab into the tabstrip at the background.
   void AddTabAtBackground(int index, GURL url) {
     chrome::NavigateParams params(browser(), url, ui::PAGE_TRANSITION_LINK);
     params.tabstrip_index = index;
-    params.disposition = NEW_BACKGROUND_TAB;
+    params.disposition = WindowOpenDisposition::NEW_BACKGROUND_TAB;
     chrome::Navigate(&params);
     content::WaitForLoadStopWithoutSuccessCheck(params.target_contents);
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BrowserWindowControllerTest);
 };
 
 // Tests that adding the first profile moves the Lion fullscreen button over
 // correctly.
@@ skipping 354 matching lines @@
   EXPECT_FALSE([fullscreenToolbarController isRevealingToolbarForTabstrip]);
   [fullscreenToolbarController resetToolbarFlag];
 
   // Switch to a non-NTP tab.
   TabStripModel* model = browser()->tab_strip_model();
   model->ActivateTabAt(1, true);
   ASSERT_FALSE([[controller() toolbarController] isLocationBarFocused]);
   EXPECT_TRUE([fullscreenToolbarController isRevealingToolbarForTabstrip]);
   [fullscreenToolbarController resetToolbarFlag];
 }