Move JoinString to the base namespace

ui/base/dragdrop/os_exchange_data_provider_aurax11.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_aurax11.h"
 
 #include "base/logging.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
@@ skipping 181 matching lines @@
     const std::vector<FileInfo>& filenames) {
   std::vector<std::string> paths;
   for (std::vector<FileInfo>::const_iterator it = filenames.begin();
        it != filenames.end();
        ++it) {
     std::string url_spec = net::FilePathToFileURL(it->path).spec();
     if (!url_spec.empty())
       paths.push_back(url_spec);
   }
 
-  std::string joined_data = JoinString(paths, '\n');
+  std::string joined_data = base::JoinString(paths, "\n");
   scoped_refptr<base::RefCountedMemory> mem(
       base::RefCountedString::TakeString(&joined_data));
   format_map_.Insert(atom_cache_.GetAtom(Clipboard::kMimeTypeURIList), mem);
 }
 
 void OSExchangeDataProviderAuraX11::SetPickledData(
     const OSExchangeData::CustomFormat& format,
     const base::Pickle& pickle) {
   const unsigned char* data =
       reinterpret_cast<const unsigned char*>(pickle.data());
@@ skipping 333 matching lines @@
 
 ///////////////////////////////////////////////////////////////////////////////
 // OSExchangeData, public:
 
 // static
 OSExchangeData::Provider* OSExchangeData::CreateProvider() {
   return new OSExchangeDataProviderAuraX11();
 }
 
 }  // namespace ui