Detach the dependency from host_content_settings_map to extension.

chrome/browser/content_settings/content_settings_pref_provider.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/content_settings/content_settings_pref_provider.h"
 
 #include <map>
 #include <string>
 #include <utility>
 
@@ skipping 549 matching lines @@
 }
 
 void PrefProvider::ShutdownOnUIThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(prefs_);
   RemoveAllObservers();
   pref_change_registrar_.RemoveAll();
   prefs_ = NULL;
 }
 
+std::string PrefProvider::GetProviderName() const {
+  return "preference";
+}
+
+SettingSource PrefProvider::GetSettingSource() const {
+  return SETTING_SOURCE_USER;
+}
+
 void PrefProvider::UpdateLastUsage(
     const ContentSettingsPattern& primary_pattern,
     const ContentSettingsPattern& secondary_pattern,
     ContentSettingsType content_type) {
   // Don't write if in incognito.
   if (is_incognito_) {
     return;
   }
 
   // Ensure that |lock_| is not held by this thread, since this function will
@@ skipping 72 matching lines @@
   lock_.Acquire();
   lock_.Release();
 #endif
 }
 
 void PrefProvider::SetClockForTesting(scoped_ptr<base::Clock> clock) {
   clock_ = clock.Pass();
 }
 
 }  // namespace content_settings