Refactor the socket API to remove onEvent callback in socket.create() function.

chrome/renderer/resources/extensions/experimental.socket_custom_bindings.js

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Custom bindings for the experimental.socket API.
-
-  var experimentalSocketNatives = requireNative('experimental_socket');
-  var GetNextSocketEventId = experimentalSocketNatives.GetNextSocketEventId;
-
-  var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
-  var sendRequest = require('sendRequest').sendRequest;
-  var lazyBG = requireNative('lazy_background_page');
-
-  chromeHidden.registerCustomHook('experimental.socket', function(api) {
-      var apiFunctions = api.apiFunctions;
-
-      apiFunctions.setHandleRequest('create', function() {
-          var args = arguments;
-          if (args.length > 1 && args[1] && args[1].onEvent) {
-            var id = GetNextSocketEventId();
-            args[1].srcId = id;
-            chromeHidden.socket.handlers[id] = args[1].onEvent;
-
-            // Keep the page alive until the event finishes.
-            // Balanced in eventHandler.
-            lazyBG.IncrementKeepaliveCount();
-          }
-          sendRequest(this.name, args, this.definition.parameters);
-          return id;
-        });
-
-      // Set up events.
-      chromeHidden.socket = {};
-      chromeHidden.socket.handlers = {};
-      chrome.experimental.socket.onEvent.addListener(function(event) {
-          var eventHandler = chromeHidden.socket.handlers[event.srcId];
-          if (eventHandler) {
-            switch (event.type) {
-              case 'writeComplete':
-              case 'connectComplete':
-                eventHandler({
-                 type: event.type,
-                        resultCode: event.resultCode,
-                        });
-              break;
-              case 'dataRead':
-                eventHandler({
-                 type: event.type,
-                        resultCode: event.resultCode,
-                        data: event.data,
-                        });
-                break;
-              default:
-                console.error('Unexpected SocketEvent, type ' + event.type);
-              break;
-            }
-            if (event.isFinalEvent) {
-              delete chromeHidden.socket.handlers[event.srcId];
-              // Balanced in 'create' handler.
-              lazyBG.DecrementKeepaliveCount();
-            }
-          }
-        });
-    });