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

content/renderer/android/phone_number_detector.h

Index: content/renderer/android/phone_number_detector.h
diff --git a/content/renderer/android/phone_number_detector.h b/content/renderer/android/phone_number_detector.h
index 37413155df96ebb8e620b0e9a3a32f97253e79ed..6503eee30b230ebfdf2eef2b4c69bee21d320c86 100644
--- a/content/renderer/android/phone_number_detector.h
+++ b/content/renderer/android/phone_number_detector.h
@@ -18,19 +18,19 @@ class CONTENT_EXPORT PhoneNumberDetector : public ContentDetector {
  public:
   PhoneNumberDetector();
   explicit PhoneNumberDetector(const std::string& region);
-  virtual ~PhoneNumberDetector();
+  ~PhoneNumberDetector() override;
 
  private:
   friend class PhoneNumberDetectorTest;
 
   // Implementation of ContentDetector.
-  virtual bool FindContent(const base::string16::const_iterator& begin,
-                           const base::string16::const_iterator& end,
-                           size_t* start_pos,
-                           size_t* end_pos,
-                           std::string* content_text) override;
-  virtual GURL GetIntentURL(const std::string& content_text) override;
-  virtual size_t GetMaximumContentLength() override;
+  bool FindContent(const base::string16::const_iterator& begin,
+                   const base::string16::const_iterator& end,
+                   size_t* start_pos,
+                   size_t* end_pos,
+                   std::string* content_text) override;
+  GURL GetIntentURL(const std::string& content_text) override;
+  size_t GetMaximumContentLength() override;
 
   const std::string region_code_;