Remove the "one at a time" restriction from the browsingData API

chrome/browser/extensions/api/browsing_data/browsing_data_api.h

 // Copyright (c) 2012 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.
 
 // Defines the Chrome Extensions BrowsingData API functions, which entail
 // clearing browsing data, and clearing the browser's cache (which, let's be
 // honest, are the same thing), as specified in the extension API JSON.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_BROWSING_DATA_BROWSING_DATA_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_BROWSING_DATA_BROWSING_DATA_API_H_
@@ skipping 33 matching lines @@
 // Option keys.
 extern const char kExtensionsKey[];
 extern const char kOriginTypesKey[];
 extern const char kProtectedWebKey[];
 extern const char kSinceKey[];
 extern const char kUnprotectedWebKey[];
 
 // Errors!
 extern const char kBadDataTypeDetails[];
 extern const char kDeleteProhibitedError[];
-extern const char kOneAtATimeError[];
 
 }  // namespace extension_browsing_data_api_constants
 
 class BrowsingDataSettingsFunction : public UIThreadExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("browsingData.settings", BROWSINGDATA_SETTINGS)
 
   // ExtensionFunction:
   ResponseAction Run() override;
 
@@ skipping 235 matching lines @@
                              BROWSINGDATA_REMOVEWEBSQL)
 
  protected:
   ~BrowsingDataRemoveWebSQLFunction() override {}
 
   // BrowsingDataRemoverFunction:
   int GetRemovalMask() override;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_BROWSING_DATA_BROWSING_DATA_API_H_