Revert "Allow MessageFilters to restrict listening to specific message classes"

chrome/browser/spellchecker/spellcheck_message_filter.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/spellchecker/spellcheck_message_filter.h"
 
 #include <algorithm>
 #include <functional>
 
 #include "base/bind.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/spellchecker/spellcheck_factory.h"
 #include "chrome/browser/spellchecker/spellcheck_host_metrics.h"
 #include "chrome/browser/spellchecker/spellcheck_service.h"
 #include "chrome/browser/spellchecker/spelling_service_client.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/spellcheck_marker.h"
 #include "chrome/common/spellcheck_messages.h"
 #include "content/public/browser/render_process_host.h"
 #include "net/url_request/url_fetcher.h"
 
 using content::BrowserThread;
 
 SpellCheckMessageFilter::SpellCheckMessageFilter(int render_process_id)
-    : BrowserMessageFilter(SpellCheckMsgStart),
-      render_process_id_(render_process_id),
+    : render_process_id_(render_process_id),
       client_(new SpellingServiceClient) {
 }
 
 void SpellCheckMessageFilter::OverrideThreadForMessage(
     const IPC::Message& message, BrowserThread::ID* thread) {
   // IPC messages arrive on IO thread, but spellcheck data lives on UI thread.
   // The message filter overrides the thread for these messages because they
   // access spellcheck data.
   if (message.type() == SpellCheckHostMsg_RequestDictionary::ID ||
       message.type() == SpellCheckHostMsg_NotifyChecked::ID ||
@@ skipping 144 matching lines @@
                base::Unretained(this),
                route_id,
                identifier,
                markers));
 }
 #endif
 
 SpellcheckService* SpellCheckMessageFilter::GetSpellcheckService() const {
   return SpellcheckServiceFactory::GetForRenderProcessId(render_process_id_);
 }