Turn on enforce-in-pdf Clang plugin flag.

chrome/browser/pdf/pdf_extension_test.cc

 // Copyright 2014 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 <stddef.h>
 
 #include <vector>
 
 #include "base/base_paths.h"
 #include "base/files/file_enumerator.h"
@@ skipping 279 matching lines @@
   LoadAllPdfsTest("pdf_private", GetParam());
 #endif
   // Load public PDFs.
   LoadAllPdfsTest("pdf", GetParam());
 }
 
 class DisablePluginHelper : public content::DownloadManager::Observer,
                             public content::NotificationObserver {
  public:
   DisablePluginHelper() {}
-
-  virtual ~DisablePluginHelper() {}
+  ~DisablePluginHelper() override {}
 
   void DisablePlugin(Profile* profile) {
     registrar_.Add(this, chrome::NOTIFICATION_PLUGIN_ENABLE_STATUS_CHANGED,
                    content::Source<Profile>(profile));
     scoped_refptr<PluginPrefs> prefs(PluginPrefs::GetForProfile(profile));
     DCHECK(prefs.get());
     prefs->EnablePluginGroup(
         false, base::UTF8ToUTF16(ChromeContentClient::kPDFPluginName));
     // Wait until the plugin has been disabled.
     disable_run_loop_.Run();
@@ skipping 539 matching lines @@
   int tab_count = browser()->tab_strip_model()->count();
   ASSERT_EQ(2, tab_count);
 
   content::WebContents* active_web_contents =
       browser()->tab_strip_model()->GetActiveWebContents();
   ASSERT_NE(web_contents, active_web_contents);
 
   const GURL& url = active_web_contents->GetURL();
   ASSERT_EQ(std::string("http://www.example.com/"), url.spec());
 }