Enable/disable extensions upon changes in blacklist.

chrome/browser/extensions/extension_prefs.h

Index: chrome/browser/extensions/extension_prefs.h
diff --git a/chrome/browser/extensions/extension_prefs.h b/chrome/browser/extensions/extension_prefs.h
index cc8d5102e0d5905ddc311e7b4ff256a23d46bd68..8832a553dcdf6858869f9a4adfe448666b1f0d31 100644
--- a/chrome/browser/extensions/extension_prefs.h
+++ b/chrome/browser/extensions/extension_prefs.h
@@ -190,6 +190,12 @@ class ExtensionPrefs : public ExtensionScopedPrefs,
   // Called to change the extension's state when it is enabled/disabled.
   void SetExtensionState(const std::string& extension_id, Extension::State);
 
+  // Called to change the extension's state when it is enabled/disabled.
+  void SetExtensionGreylisted(const std::string& extension_id, bool state);
+
+  // Checks whether |extension_id| is marked as greylisted.
+  bool IsExtensionGreylisted(const std::string& extension_id);
+
   // Populates |out| with the ids of all installed extensions.
   void GetExtensions(ExtensionIdList* out);