Eliminate the dependency of Profile from TtsMessageFilter.

chrome/browser/speech/tts_platform.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/speech/tts_platform.h"
 
 #include <string>
 
-bool TtsPlatformImpl::LoadBuiltInTtsExtension(Profile* profile) {
+bool TtsPlatformImpl::LoadBuiltInTtsExtension(
+    content::BrowserContext* browser_context) {
   return false;
 }
 
 std::string TtsPlatformImpl::error() {
   return error_;
 }
 
 void TtsPlatformImpl::clear_error() {
   error_ = std::string();
 }
 
 void TtsPlatformImpl::set_error(const std::string& error) {
   error_ = error;
 }
 
 void TtsPlatformImpl::WillSpeakUtteranceWithVoice(const Utterance* utterance,
                                                   const VoiceData& voice_data) {
 }