Make ExtensionContentSettingsStore refcounted.

chrome/browser/extensions/extension_content_settings_store.h

Index: chrome/browser/extensions/extension_content_settings_store.h
diff --git a/chrome/browser/extensions/extension_content_settings_store.h b/chrome/browser/extensions/extension_content_settings_store.h
index 1f090a68ab29a5efaa4f328a60d40fcc3ec486a0..cdba78440ec9ba10ab2869a8dcff4b7654cd4667 100644
--- a/chrome/browser/extensions/extension_content_settings_store.h
+++ b/chrome/browser/extensions/extension_content_settings_store.h
@@ -27,7 +27,8 @@ class ListValue;
 // by the content_settings::ExtensionProvider to integrate its settings into the
 // HostContentSettingsMap and by the content settings extension API to provide
 // extensions with access to content settings.
-class ExtensionContentSettingsStore {
+class ExtensionContentSettingsStore
+    : public base::RefCountedThreadSafe<ExtensionContentSettingsStore> {
  public:
   class Observer {
    public:
@@ -38,14 +39,9 @@ class ExtensionContentSettingsStore {
     virtual void OnContentSettingChanged(
         const std::string& extension_id,
         bool incognito) = 0;
-
-    // Called when the ExtensionContentSettingsStore is being destroyed, so
-    // observers can invalidate their weak references.
-    virtual void OnDestruction() = 0;
   };
 
   ExtensionContentSettingsStore();
-  virtual ~ExtensionContentSettingsStore();
 
   // //////////////////////////////////////////////////////////////////////////
 
@@ -116,6 +112,8 @@ class ExtensionContentSettingsStore {
   void RemoveObserver(Observer* observer);
 
  private:
+  friend class base::RefCountedThreadSafe<ExtensionContentSettingsStore>;
+
   struct ExtensionEntry;
   struct ContentSettingSpec {
     ContentSettingSpec(const ContentSettingsPattern& primary_pattern,
@@ -135,6 +133,8 @@ class ExtensionContentSettingsStore {
 
   typedef std::list<ContentSettingSpec> ContentSettingSpecList;
 
+  virtual ~ExtensionContentSettingsStore();
+
   ContentSetting GetContentSettingFromSpecList(
       const GURL& embedded_url,
       const GURL& top_level_url,
@@ -160,8 +160,6 @@ class ExtensionContentSettingsStore {
   void NotifyOfContentSettingChanged(const std::string& extension_id,
                                      bool incognito);
 
-  void NotifyOfDestruction();
-
   bool OnCorrectThread();
 
   ExtensionEntryMap entries_;