Allow script to request durable storage permission (chrome side)

content/child/permissions/permission_dispatcher.h

Index: content/child/permissions/permission_dispatcher.h
diff --git a/content/child/permissions/permission_dispatcher.h b/content/child/permissions/permission_dispatcher.h
index 17410e6b8214f7509447a29d901613d379d2e53f..9a2cb751a2d94105e858084ca2e7d79cbd20826f 100644
--- a/content/child/permissions/permission_dispatcher.h
+++ b/content/child/permissions/permission_dispatcher.h
@@ -37,6 +37,8 @@ class PermissionDispatcher : public blink::WebPermissionClient,
   virtual ~PermissionDispatcher();
 
   // blink::WebPermissionClient implementation.
+  virtual void requestDurablePermission(const blink::WebURL&,
+      blink::WebPermissionQueryCallback*);
   virtual void queryPermission(blink::WebPermissionType type,
                                const blink::WebURL& origin,
                                blink::WebPermissionQueryCallback* callback);