Upstream helper method to clear data using BrowserStateDataRemover.

ios/chrome/browser/signin/browser_state_data_remover.h

 // Copyright 2014 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 IOS_CHROME_BROWSER_SIGNIN_BROWSER_STATE_DATA_REMOVER_H_
 #define IOS_CHROME_BROWSER_SIGNIN_BROWSER_STATE_DATA_REMOVER_H_
 
 #include "base/ios/block_types.h"
 #include "base/mac/scoped_nsobject.h"
 #include "ios/chrome/browser/browsing_data/ios_chrome_browsing_data_remover.h"
 
 namespace ios {
 class ChromeBrowserState;
 }
 
 // Helper that wipes all the data in the given browser state. This deletes all
 // browsing data and all the bookmarks.
 class BrowserStateDataRemover {
  public:
   explicit BrowserStateDataRemover(ios::ChromeBrowserState* browser_state);
   ~BrowserStateDataRemover();
 
+  // Removes all bookmarks, clears all browsing data, last signed-in username
+  // and then runs |completion|. The user must be signed out when this method
+  // is called.
+  static void ClearData(ios::ChromeBrowserState* browser_state,
+                        ProceduralBlock completion);
+
   // If set then the last username will be removed from the browser state prefs
   // after the data has been wiped.
   void SetForgetLastUsername();
 
   // Wipes all the data in the browser state and invokes |callback| when done.
   // This can be called only once, and this object deletes itself after invoking
   // the callback.
   void RemoveBrowserStateData(ProceduralBlock callback);
 
  private:
   void NotifyWithDetails(
       const IOSChromeBrowsingDataRemover::NotificationDetails& details);
 
   ios::ChromeBrowserState* browser_state_;
   base::scoped_nsprotocol<ProceduralBlock> callback_;
   IOSChromeBrowsingDataRemover::CallbackSubscription callback_subscription_;
   bool forget_last_username_;
 };
 
 #endif  // IOS_CHROME_BROWSER_SIGNIN_BROWSER_STATE_DATA_REMOVER_H_