Fix some uses of global variables in transient pages.

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 > 3 && args[3] && args[3].onEvent) {
             var id = GetNextSocketEventId();
             args[3].srcId = id;
             chromeHidden.socket.handlers[id] = args[3].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];
@@ skipping 12 matching lines @@
                         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();
             }
           }
         });
     });