Fix the Declarative WebRequest API for <webview>

chrome/renderer/resources/extensions/web_view_experimental.js

Index: chrome/renderer/resources/extensions/web_view_experimental.js
diff --git a/chrome/renderer/resources/extensions/web_view_experimental.js b/chrome/renderer/resources/extensions/web_view_experimental.js
index 62b3a249e6ab89982e6a5615ecca6481ff9873be..311de4640502b8c6e4442890885c1fe30b36ff5b 100644
--- a/chrome/renderer/resources/extensions/web_view_experimental.js
+++ b/chrome/renderer/resources/extensions/web_view_experimental.js
@@ -122,21 +122,6 @@ var WebViewContextMenus = utils.expose(
     'WebViewContextMenus', WebViewContextMenusImpl,
     { functions: ['create', 'remove', 'removeAll', 'update'] });
 
-/**
- * @private
- */
-WebViewInternal.prototype.maybeAttachWebRequestEventToObject =
-    function(obj, eventName, webRequestEvent) {
-  Object.defineProperty(
-      obj,
-      eventName,
-      {
-        get: webRequestEvent,
-        enumerable: true
-      }
-  );
-};
-
 /** @private */
 WebViewInternal.prototype.maybeHandleContextMenu = function(e, webViewEvent) {
   var requestId = e.requestId;