[Do not commit] Track revocations in content_settings::Observer

components/content_settings/core/browser/content_settings_pref.cc

Index: components/content_settings/core/browser/content_settings_pref.cc
diff --git a/components/content_settings/core/browser/content_settings_pref.cc b/components/content_settings/core/browser/content_settings_pref.cc
index e1e2b332e5ac1b509780d02a937c906cf4c583a8..44a9f80b15092c45a7858f04e96f2fdb67ba3967 100644
--- a/components/content_settings/core/browser/content_settings_pref.cc
+++ b/components/content_settings/core/browser/content_settings_pref.cc
@@ -107,6 +107,8 @@ bool ContentSettingsPref::SetWebsiteSetting(
   // At this point take the ownership of the |in_value|.
   scoped_ptr<base::Value> value(in_value);
 
+  ContentSetting previous_value = CONTENT_SETTING_DEFAULT;
+
   // Update in memory value map.
   OriginIdentifierValueMap* map_to_modify = &incognito_value_map_;
   if (!is_incognito_)
@@ -131,14 +133,14 @@ bool ContentSettingsPref::SetWebsiteSetting(
   }
   // Update the content settings preference.
   if (!is_incognito_) {
-    UpdatePref(primary_pattern,
-               secondary_pattern,
-               resource_identifier,
-               value.get());
+    previous_value = UpdatePref(primary_pattern,
+                                secondary_pattern,
+                                resource_identifier,
+                                value.get());
   }
 
-  notify_callback_.Run(
-      primary_pattern, secondary_pattern, content_type_, resource_identifier);
+  notify_callback_.Run(primary_pattern, secondary_pattern, content_type_,
+                       previous_value, resource_identifier);
 
   return true;
 }
@@ -174,6 +176,7 @@ void ContentSettingsPref::ClearAllContentSettingsRules() {
   notify_callback_.Run(ContentSettingsPattern(),
                        ContentSettingsPattern(),
                        content_type_,
+                       CONTENT_SETTING_DEFAULT,
                        ResourceIdentifier());
 }
 
@@ -376,10 +379,11 @@ void ContentSettingsPref::OnPrefChanged() {
   notify_callback_.Run(ContentSettingsPattern(),
                        ContentSettingsPattern(),
                        content_type_,
+                       CONTENT_SETTING_DEFAULT,
                        ResourceIdentifier());
 }
 
-void ContentSettingsPref::UpdatePref(
+ContentSetting ContentSettingsPref::UpdatePref(
     const ContentSettingsPattern& primary_pattern,
     const ContentSettingsPattern& secondary_pattern,
     const ResourceIdentifier& resource_identifier,
@@ -388,6 +392,8 @@ void ContentSettingsPref::UpdatePref(
   // send out notifications (by |~DictionaryPrefUpdate|).
   AssertLockNotHeld();
 
+  ContentSetting old_content_setting = CONTENT_SETTING_DEFAULT;
+
   base::AutoReset<bool> auto_reset(&updating_preferences_, true);
   {
     DictionaryPrefUpdate update(prefs_, pref_name_);
@@ -407,6 +413,11 @@ void ContentSettingsPref::UpdatePref(
     }
 
     if (settings_dictionary) {
+      int old_setting = CONTENT_SETTING_DEFAULT;
+      settings_dictionary->GetIntegerWithoutPathExpansion(kSettingPath,
+                                                          &old_setting);
+      old_content_setting = static_cast<ContentSetting>(old_setting);
+
       if (SupportsResourceIdentifiers(content_type_) &&
           !resource_identifier.empty()) {
         base::DictionaryValue* resource_dictionary = NULL;
@@ -414,7 +425,7 @@ void ContentSettingsPref::UpdatePref(
             kPerResourceIdentifierPrefName, &resource_dictionary);
         if (!found) {
           if (value == NULL)
-            return;  // Nothing to remove. Exit early.
+            return old_content_setting;  // Nothing to remove. Exit early.
           resource_dictionary = new base::DictionaryValue;
           settings_dictionary->Set(
               kPerResourceIdentifierPrefName, resource_dictionary);
@@ -448,6 +459,8 @@ void ContentSettingsPref::UpdatePref(
       }
     }
   }
+
+  return old_content_setting;
 }
 
 // static