Add the "virtual" keyword on method overrides that are missing it.

chrome/browser/autofill/home_address.h

 // Copyright (c) 2010 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_AUTOFILL_HOME_ADDRESS_H_
 #define CHROME_BROWSER_AUTOFILL_HOME_ADDRESS_H_
 #pragma once
 
 #include "chrome/browser/autofill/address.h"
 #include "chrome/browser/autofill/field_types.h"
 
 class FormGroup;
 
 // A specialization of Address that identifies itself as a home address.
 class HomeAddress : public Address {
  public:
   HomeAddress() {}
-  FormGroup* Clone() const { return new HomeAddress(*this); }
+  virtual FormGroup* Clone() const { return new HomeAddress(*this); }
 
  protected:
   virtual AutoFillFieldType GetLine1Type() const {
     return ADDRESS_HOME_LINE1;
   }
 
   virtual AutoFillFieldType GetLine2Type() const {
     return ADDRESS_HOME_LINE2;
   }
 
@@ skipping 16 matching lines @@
   virtual AutoFillFieldType GetCountryType() const {
     return ADDRESS_HOME_COUNTRY;
   }
 
  private:
   explicit HomeAddress(const HomeAddress& address) : Address(address) {}
   void operator=(const HomeAddress& address);  // Not implemented.
 };
 
 #endif  // CHROME_BROWSER_AUTOFILL_HOME_ADDRESS_H_