Content Settings: Add RevocationObserver to measure when permissions are revoked

components/content_settings/core/browser/host_content_settings_map.h

Index: components/content_settings/core/browser/host_content_settings_map.h
diff --git a/components/content_settings/core/browser/host_content_settings_map.h b/components/content_settings/core/browser/host_content_settings_map.h
index 927305765c5d708efa37b1f53d6afcfbffb2260c..77a7fe723fe4ee0d8af21a1e37a42847df57ba15 100644
--- a/components/content_settings/core/browser/host_content_settings_map.h
+++ b/components/content_settings/core/browser/host_content_settings_map.h
@@ -271,6 +271,9 @@ class HostContentSettingsMap : public content_settings::Observer,
   void AddObserver(content_settings::Observer* observer);
   void RemoveObserver(content_settings::Observer* observer);
 
+  void AddRevocationObserver(content_settings::RevocationObserver* observer);
+  void RemoveRevocationObserver(content_settings::RevocationObserver* observer);
+
   // Schedules any pending lossy website settings to be written to disk.
   void FlushLossyWebsiteSettings();
 
@@ -321,6 +324,11 @@ class HostContentSettingsMap : public content_settings::Observer,
       const std::string& resource_identifier,
       content_settings::SettingInfo* info) const;
 
+  void NotifyRevocation(const GURL& primary_url,
+                        const GURL& secondary_url,
+                        ContentSettingsType content_type,
+                        const std::string& resource_identifier);
+
   static scoped_ptr<base::Value> GetContentSettingValueAndPatterns(
       const content_settings::ProviderInterface* provider,
       const GURL& primary_url,
@@ -364,6 +372,8 @@ class HostContentSettingsMap : public content_settings::Observer,
   base::ThreadChecker thread_checker_;
 
   base::ObserverList<content_settings::Observer> observers_;
+  base::ObserverList<content_settings::RevocationObserver>
+      revocation_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(HostContentSettingsMap);
 };