Replace string16 with base::string16.

chrome/browser/download/download_file_picker.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 "chrome/browser/download/download_file_picker.h"
 
 #include "base/metrics/histogram.h"
 #include "chrome/browser/download/download_prefs.h"
 #include "chrome/browser/platform_util.h"
 #include "chrome/browser/ui/chrome_select_file_policy.h"
@@ skipping 64 matching lines @@
     file_type_info.extensions.resize(1);
     file_type_info.extensions[0].push_back(extension);
   }
   file_type_info.include_all_files = true;
   file_type_info.support_drive = true;
   gfx::NativeWindow owning_window = web_contents ?
       platform_util::GetTopLevel(web_contents->GetView()->GetNativeView()) :
       NULL;
 
   select_file_dialog_->SelectFile(ui::SelectFileDialog::SELECT_SAVEAS_FILE,
-                                  string16(),
+                                  base::string16(),
                                   suggested_path_,
                                   &file_type_info,
                                   0,
                                   base::FilePath::StringType(),
                                   owning_window,
                                   NULL);
 }
 
 DownloadFilePicker::~DownloadFilePicker() {
 }
@@ skipping 17 matching lines @@
   // Deletes |this|
 }
 
 // static
 void DownloadFilePicker::ShowFilePicker(DownloadItem* item,
                                         const base::FilePath& suggested_path,
                                         const FileSelectedCallback& callback) {
   new DownloadFilePicker(item, suggested_path, callback);
   // DownloadFilePicker deletes itself.
 }