Update {virtual,override} to follow C++11 style in chrome.

chrome/browser/ui/pdf/chrome_pdf_web_contents_helper_client.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_PDF_CHROME_PDF_WEB_CONTENTS_HELPER_CLIENT_H_
 #define CHROME_BROWSER_UI_PDF_CHROME_PDF_WEB_CONTENTS_HELPER_CLIENT_H_
 
 #include "base/macros.h"
 #include "components/pdf/browser/pdf_web_contents_helper_client.h"
 
 class ChromePDFWebContentsHelperClient
     : public pdf::PDFWebContentsHelperClient {
  public:
   ChromePDFWebContentsHelperClient();
-  virtual ~ChromePDFWebContentsHelperClient();
+  ~ChromePDFWebContentsHelperClient() override;
 
  private:
   // pdf::PDFWebContentsHelperClient:
-  virtual void UpdateLocationBar(content::WebContents* contents) override;
+  void UpdateLocationBar(content::WebContents* contents) override;
 
-  virtual void UpdateContentRestrictions(content::WebContents* contents,
-                                         int content_restrictions) override;
+  void UpdateContentRestrictions(content::WebContents* contents,
+                                 int content_restrictions) override;
 
-  virtual void OnPDFHasUnsupportedFeature(
-      content::WebContents* contents) override;
+  void OnPDFHasUnsupportedFeature(content::WebContents* contents) override;
 
-  virtual void OnSaveURL(content::WebContents* contents) override;
+  void OnSaveURL(content::WebContents* contents) override;
 
-  virtual void OnShowPDFPasswordDialog(
+  void OnShowPDFPasswordDialog(
       content::WebContents* contents,
       const base::string16& prompt,
       const pdf::PasswordDialogClosedCallback& callback) override;
 
   DISALLOW_COPY_AND_ASSIGN(ChromePDFWebContentsHelperClient);
 };
 
 void ShowPDFPasswordDialog(content::WebContents* web_contents,
                            const base::string16& prompt,
                            const pdf::PasswordDialogClosedCallback& callback);
 
 #endif  // CHROME_BROWSER_UI_PDF_CHROME_PDF_WEB_CONTENTS_HELPER_CLIENT_H_