Remove some wstrings in test_shell.

webkit/tools/test_shell/test_shell_mac.mm

 // Copyright (c) 2011 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 <ApplicationServices/ApplicationServices.h>
 #import <Cocoa/Cocoa.h>
 #import <objc/objc-runtime.h>
 #include <sys/stat.h>
 
 #include "webkit/tools/test_shell/test_shell.h"
@@ skipping 514 matching lines @@
     NSWindow* window = *iter;
     WindowMap::iterator it = window_map_.Get().find(window);
     if (it != window_map_.Get().end())
       it->second->DumpBackForwardList(result);
     else
       LOG(ERROR) << "Failed to find shell for window during dump";
   }
 }
 
 void TestShell::LoadURLForFrame(const GURL& url,
-                                const std::wstring& frame_name) {
+                                const string16& frame_name) {
   if (!url.is_valid())
     return;
 
   if (IsSVGTestURL(url)) {
     SizeTo(kSVGTestWindowWidth, kSVGTestWindowHeight);
   } else {
     // only resize back to the default when running tests
     if (layout_test_mode())
       SizeToDefault();
   }
 
   navigation_controller_->LoadEntry(
-      new TestNavigationEntry(-1, url, std::wstring(), frame_name));
+      new TestNavigationEntry(-1, url, frame_name));
 }
 
 bool TestShell::PromptForSaveFile(const wchar_t* prompt_title,
                                   FilePath* result)
 {
   NSSavePanel* save_panel = [NSSavePanel savePanel];
 
   /* set up new attributes */
   [save_panel setRequiredFileType:@"txt"];
   [save_panel setMessage:
@@ skipping 132 matching lines @@
   return false;
 }
 
 void DidLoadPlugin(const std::string& filename) {
 }
 
 void DidUnloadPlugin(const std::string& filename) {
 }
 
 }  // namespace webkit_glue