Makes the auto fill dialogs match the mocks.

chrome/browser/autofill/autofill_dialog.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_AUTOFILL_DIALOG_H_
 #define CHROME_BROWSER_AUTOFILL_AUTOFILL_DIALOG_H_
 
 #include <vector>
 
 #include "chrome/browser/autofill/autofill_profile.h"
 #include "chrome/browser/autofill/credit_card.h"
 #include "gfx/native_widget_types.h"
 
 class Profile;
 
 // An interface the AutoFill dialog uses to notify its clients (observers) when
 // the user has applied changes to the AutoFill profile data.
 class AutoFillDialogObserver {
  public:
   // The user has confirmed changes by clicking "Apply" or "OK".  Any of the
-  // parameters may be NULL.
+  // parameters may be NULL. A NULL parameter is treated as not changing the
+  // existing data. For example, |OnAutoFillDialogApply(new_profiles, NULL)|
+  // only sets the profiles and not the credit cards.
   virtual void OnAutoFillDialogApply(
       std::vector<AutoFillProfile>* profiles,
       std::vector<CreditCard>* credit_cards) = 0;
 
  protected:
   virtual ~AutoFillDialogObserver() {}
 };
 
 // Shows the AutoFill dialog, which allows the user to edit profile information.
-// |profile| is profile from which you can get vectors of of autofill profiles
-// that contains the current profile information and credit cards.
-// The dialog fills out the profile fields using this data.
+// |profile| is profile from which you can get vectors of autofill profiles that
+// contains the current profile information and credit cards.  The dialog fills
+// out the profile fields using this data.
 //
 // |observer| will be notified by OnAutoFillDialogAccept when the user has
 // applied changes.  May not be NULL.
 //
 // The |parent| parameter (currently only used on Windows) specifies the parent
 // view in the view hierarchy.  May be NULL on Mac and gtk.
 void ShowAutoFillDialog(gfx::NativeView parent,
                         AutoFillDialogObserver* observer,
                         Profile* profile);
 
 #endif  // CHROME_BROWSER_AUTOFILL_AUTOFILL_DIALOG_H_