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

chrome/browser/ui/pdf/chrome_pdf_web_contents_helper_client.h

Index: chrome/browser/ui/pdf/chrome_pdf_web_contents_helper_client.h
diff --git a/chrome/browser/ui/pdf/chrome_pdf_web_contents_helper_client.h b/chrome/browser/ui/pdf/chrome_pdf_web_contents_helper_client.h
index 686174cb7644323c0e065096ea3e174590cf9615..a95a46d1a7e2a19d8202aa4180b2e9ae202abec2 100644
--- a/chrome/browser/ui/pdf/chrome_pdf_web_contents_helper_client.h
+++ b/chrome/browser/ui/pdf/chrome_pdf_web_contents_helper_client.h
@@ -12,21 +12,20 @@ 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;