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

chrome/browser/search_engines/search_provider_install_state_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/search_engines/search_provider_install_state_message_filter.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/render_messages.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "url/gurl.h"
 
 using content::BrowserThread;
 
 SearchProviderInstallStateMessageFilter::
 SearchProviderInstallStateMessageFilter(
     int render_process_id,
     Profile* profile)
-    : BrowserMessageFilter(ChromeMsgStart),
-      provider_data_(profile,
+    : provider_data_(profile,
                      content::RenderProcessHost::FromID(render_process_id)),
       is_off_the_record_(profile->IsOffTheRecord()),
       weak_factory_(this) {
   // This is initialized by RenderProcessHostImpl. Do not add any non-trivial
   // initialization here. Instead do it lazily when required.
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }
 
 bool SearchProviderInstallStateMessageFilter::OnMessageReceived(
     const IPC::Message& message,
@@ skipping 67 matching lines @@
     IPC::Message* reply_msg) {
   DCHECK(reply_msg);
   search_provider::InstallState install_state =
       GetSearchProviderInstallState(page_location, requested_host);
 
   ChromeViewHostMsg_GetSearchProviderInstallState::WriteReplyParams(
       reply_msg,
       install_state);
   Send(reply_msg);
 }