Update some uses of UTF conversions in chrome/browser to use the base:: namespace.

chrome/browser/spellchecker/feedback_unittest.cc

 // Copyright (c) 2013 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.
 //
 // Unit tests for |Feedback| object.
 
 #include "chrome/browser/spellchecker/feedback.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+using base::ASCIIToUTF16;
+
 namespace spellcheck {
 
 namespace {
 
 // Identifier for a renderer process.
 const int kRendererProcessId = 7;
 
 // Hash identifier for a misspelling.
 const uint32 kMisspellingHash = 42;
 
@@ skipping 226 matching lines @@
                   kMisspellingStart,
                   kMisspellingLength,
                   std::vector<base::string16>(1, kSuggestion),
                   kMisspellingHash));
   feedback_.GetMisspelling(kMisspellingHash)->action.Finalize();
   feedback_.EraseFinalizedMisspellings(kRendererProcessId);
   EXPECT_TRUE(feedback_.FindMisspellings(kMisspelledWord).empty());
 }
 
 }  // namespace spellcheck