Allow OSExchangeData::Provider to be overridden at run time.

ui/base/dragdrop/os_exchange_data_provider_aura.cc

 // 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.
 
 #include "ui/base/dragdrop/os_exchange_data_provider_aura.h"
 
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
 #include "net/base/filename_util.h"
 #include "ui/base/clipboard/clipboard.h"
@@ skipping 199 matching lines @@
 
   GURL test_url(string_);
   if (!test_url.is_valid())
     return false;
 
   if (url)
     *url = test_url;
   return true;
 }
 
-///////////////////////////////////////////////////////////////////////////////
-// OSExchangeData, public:
-
-// static
-OSExchangeData::Provider* OSExchangeData::CreateProvider() {
-  return new OSExchangeDataProviderAura();
-}
-
 }  // namespace ui