Content Settings: Add RevocationObserver to measure when permissions are revoked

chrome/browser/content_settings/content_settings_mock_observer.cc

 // Copyright (c) 2011 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_mock_observer.h"
 
 namespace content_settings {
 
 MockObserver::MockObserver() {
 }
 
-MockObserver::~MockObserver()  {
+MockObserver::~MockObserver() {
+}
+
+MockRevocationObserver::MockRevocationObserver() {
+}
+
+MockRevocationObserver::~MockRevocationObserver() {
+}
+
+void MockRevocationObserver::OnContentSettingChanged(
+    const ContentSettingsPattern& primary_pattern,
+    const ContentSettingsPattern& secondary_pattern,
+    ContentSettingsType content_type,
+    std::string resource_identifier) {
 }
 
 }  // namespace content_settings