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

chrome/renderer/spellchecker/spellcheck_unittest.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 "webkit/glue/webkit_glue.h"
 
 #include "base/file_util.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/platform_file.h"
@@ skipping 829 matching lines @@
   TestSpellCheckParagraph(text, expected);
 }
 
 // We also skip RequestSpellCheck tests on Mac, because a system spellchecker
 // is used on Mac instead of SpellCheck::RequestTextChecking.
 
 // Make sure RequestTextChecking does not crash if input is empty.
 TEST_F(SpellCheckTest, RequestSpellCheckWithEmptyString) {
   MockTextCheckingCompletion completion;
 
-  const string16 text = ASCIIToUTF16("");
-  spell_check()->RequestTextChecking(text, 0, &completion);
+  spell_check()->RequestTextChecking(string16(), 0, &completion);
 
   MessageLoop::current()->RunAllPending();
 
   EXPECT_EQ(completion.completion_count_, 1U);
 }
 
 // A simple test case having no misspellings.
 TEST_F(SpellCheckTest, RequestSpellCheckWithoutMisspelling) {
   MockTextCheckingCompletion completion;
 
@@ skipping 103 matching lines @@
   InitializeSpellCheck("en-US");
 
   // Calls PostDelayedSpellCheckTask instead of OnInit here for simplicity.
   spell_check()->PostDelayedSpellCheckTask();
   MessageLoop::current()->RunAllPending();
   for (int i = 0; i < 3; ++i)
     EXPECT_EQ(completion[i].completion_count_, 1U);
 }
 
 #endif