chrome: Instead of doing a conversion just use string16().

chrome/browser/ui/tab_modal_confirm_dialog_browsertest.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/ui/tab_modal_confirm_dialog_browsertest.h"
 
 #include "base/bind.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/ui/browser_dialogs.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/tab_modal_confirm_dialog_delegate.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 class MockTabModalConfirmDialogDelegate : public TabModalConfirmDialogDelegate {
  public:
   explicit MockTabModalConfirmDialogDelegate(content::WebContents* web_contents)
       : TabModalConfirmDialogDelegate(web_contents) {}
 
   virtual string16 GetTitle() OVERRIDE {
-    return ASCIIToUTF16("");
+    return string16()
   }
   virtual string16 GetMessage() OVERRIDE {
-    return ASCIIToUTF16("");
+    return string16();
   }
 
   MOCK_METHOD0(OnAccepted, void());
   MOCK_METHOD0(OnCanceled, void());
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockTabModalConfirmDialogDelegate);
 };
 
 TabModalConfirmDialogTest::TabModalConfirmDialogTest()
@@ skipping 57 matching lines @@
   EXPECT_CALL(*delegate_, OnCanceled());
   delegate_->Cancel();
 }
 
 IN_PROC_BROWSER_TEST_F(TabModalConfirmDialogTest, Quit) {
   EXPECT_CALL(*delegate_, OnCanceled());
   MessageLoopForUI::current()->PostTask(FROM_HERE,
                                         base::Bind(&BrowserList::AttemptExit));
   ui_test_utils::RunMessageLoop();
 }