Move PrefMember and PrefChangeRegistrar to api directory.

chrome/browser/api/prefs/pref_change_registrar.cc

 // Copyright (c) 2010 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/prefs/pref_change_registrar.h"
+#include "chrome/browser/api/prefs/pref_change_registrar.h"
 
 #include "base/logging.h"
 #include "chrome/browser/prefs/pref_service.h"
 
 PrefChangeRegistrar::PrefChangeRegistrar() : service_(NULL) {}
 
 PrefChangeRegistrar::~PrefChangeRegistrar() {
   // If you see an invalid memory access in this destructor, this
   // PrefChangeRegistrar might be subscribed to an OffTheRecordProfileImpl that
   // has been destroyed. This should not happen any more but be warned.
@@ skipping 44 matching lines @@
          it != observers_.end(); ++it) {
       service_->RemovePrefObserver(it->first.c_str(), it->second);
     }
     observers_.clear();
   }
 }
 
 bool PrefChangeRegistrar::IsEmpty() const {
   return observers_.empty();
 }