Remove last usage functions from HostContentSettingsMap and clean up prefs

content/public/browser/permission_manager.h

Index: content/public/browser/permission_manager.h
diff --git a/content/public/browser/permission_manager.h b/content/public/browser/permission_manager.h
index dbf197b9d989087453e01c1d038b96579693e9b8..54de7a2ad9beb309917fb6da914f392baa663b7c 100644
--- a/content/public/browser/permission_manager.h
+++ b/content/public/browser/permission_manager.h
@@ -77,12 +77,6 @@ class CONTENT_EXPORT PermissionManager {
                                const GURL& requesting_origin,
                                const GURL& embedding_origin) = 0;
 
-  // Registers a permission usage.
-  // TODO(mlamouri): see if we can remove this from the PermissionManager.
-  virtual void RegisterPermissionUsage(PermissionType permission,
-                                       const GURL& requesting_origin,
-                                       const GURL& embedding_origin) = 0;
-
   // Runs the given |callback| whenever the |permission| associated with the
   // pair { requesting_origin, embedding_origin } changes.
   // Returns the subscription_id to be used to unsubscribe. Can be