DevTools: run user callback inside promise for promisified domains

third_party/WebKit/Source/devtools/front_end/protocol/InspectorBackend.js

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 581 matching lines @@
     var errorMessage;
     /**
      * @param {string} message
      */
     function onError(message) {
       console.error(message);
       errorMessage = message;
     }
     var userCallback = (args.length && typeof args.peekLast() === 'function') ? args.pop() : null;
     var params = this._prepareParameters(method, signature, args, !userCallback, onError);
+    var responseArguments;
     if (errorMessage)
       return Promise.reject(new Error(errorMessage));

[pfeldman, 2017/02/16 22:43:02]

You aren't calling it here, are you?

     else
-      return new Promise(promiseAction.bind(this));
+      return new Promise(promiseAction.bind(this)).then(runUserCallback);
 
     /**
-     * @param {function(?)} resolve
+     * @param {function()} resolve
      * @param {function(!Error)} reject
      * @this {Protocol.InspectorBackend._AgentPrototype}
      */
     function promiseAction(resolve, reject) {
       /**
        * @param {...*} vararg
        */
       function callback(vararg) {
-        var result = userCallback ? userCallback.apply(null, arguments) : undefined;
-        resolve(result);
+        responseArguments = arguments;
+        resolve();
       }
       this._target._wrapCallbackAndSendMessageObject(this._domain, method, params, callback);
     }
+
+    function runUserCallback() {

[pfeldman, 2017/02/16 22:43:02]

You are changing the order of callback and promise resolution, while clients
rely on it.

+      return userCallback ? userCallback.apply(null, responseArguments) : undefined;
+    }
   }
 
   /**
    * @param {string} method
    * @param {?Object} args
    * @param {?function(*)} callback
    */
   _invoke(method, args, callback) {
     this._target._wrapCallbackAndSendMessageObject(this._domain, method, args, callback);
   }
@@ skipping 89 matching lines @@
     if (Protocol.InspectorBackend.Options.dumpInspectorTimeStats)
       console.timeEnd(timingLabel);
   }
 };
 
 Protocol.InspectorBackend.Options = {
   dumpInspectorTimeStats: false,
   dumpInspectorProtocolMessages: false,
   suppressRequestErrors: false
 };