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

chrome/browser/android/signin/signin_manager_android.h

 // Copyright 2013 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_ANDROID_SIGNIN_SIGNIN_MANAGER_ANDROID_H_
 #define CHROME_BROWSER_ANDROID_SIGNIN_SIGNIN_MANAGER_ANDROID_H_
 
 #include <jni.h>
 
 #include <string>
@@ skipping 49 matching lines @@
 
   void LogInSignedInUser(JNIEnv* env, jobject obj);
 
   void ClearLastSignedInUser(JNIEnv* env, jobject obj);
 
   jboolean IsSigninAllowedByPolicy(JNIEnv* env, jobject obj);
 
   jboolean IsSignedInOnNative(JNIEnv* env, jobject obj);
 
  private:
-  virtual ~SigninManagerAndroid();
+  ~SigninManagerAndroid() override;
 
 #if defined(ENABLE_CONFIGURATION_POLICY)
   void OnPolicyRegisterDone(const std::string& dm_token,
                             const std::string& client_id);
   void OnPolicyFetchDone(bool success);
 #endif
 
   void OnBrowsingDataRemoverDone();
 
   void ClearLastSignedInUser();
@@ skipping 25 matching lines @@
   scoped_ptr<MergeSessionHelper> merge_session_helper_;
 
   PrefChangeRegistrar pref_change_registrar_;
 
   base::WeakPtrFactory<SigninManagerAndroid> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SigninManagerAndroid);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_SIGNIN_SIGNIN_MANAGER_ANDROID_H_