Add explicit base namespace to string16 users.

chrome/common/extensions/api/speech/tts_engine_manifest_handler.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/common/extensions/api/speech/tts_engine_manifest_handler.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
@@ skipping 29 matching lines @@
       extension->GetManifestData(keys::kTtsVoices));
   return info ? &info->voices : NULL;
 }
 
 TtsEngineManifestHandler::TtsEngineManifestHandler() {
 }
 
 TtsEngineManifestHandler::~TtsEngineManifestHandler() {
 }
 
-bool TtsEngineManifestHandler::Parse(Extension* extension, string16* error) {
+bool TtsEngineManifestHandler::Parse(Extension* extension,
+                                     base::string16* error) {
   scoped_ptr<TtsVoices> info(new TtsVoices);
   const base::DictionaryValue* tts_dict = NULL;
   if (!extension->manifest()->GetDictionary(keys::kTtsEngine, &tts_dict)) {
     *error = ASCIIToUTF16(errors::kInvalidTts);
     return false;
   }
 
   if (!tts_dict->HasKey(keys::kTtsVoices))
     return true;
 
@@ skipping 80 matching lines @@
 
   extension->SetManifestData(keys::kTtsVoices, info.release());
   return true;
 }
 
 const std::vector<std::string> TtsEngineManifestHandler::Keys() const {
   return SingleKey(keys::kTtsEngine);
 }
 
 }  // namespace extensions