Protect all uses of JSON.parse against exceptions.

remoting/webapp/remoting.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.
 
 'use strict';
 
 /** @suppress {duplicate} */
 var remoting = remoting || {};
 
 /** @type {remoting.HostSession} */ remoting.hostSession = null;
@@ skipping 109 matching lines @@
  * Log information about the current extension.
  * The extension manifest is loaded and parsed to extract this info.
  */
 remoting.logExtensionInfoAsync_ = function() {
   /** @type {XMLHttpRequest} */
   var xhr = new XMLHttpRequest();
   xhr.open('GET', 'manifest.json');
   xhr.onload = function(e) {
     var manifest =
         /** @type {{name: string, version: string, default_locale: string}} */
-        JSON.parse(xhr.responseText);
-    var name = chrome.i18n.getMessage('PRODUCT_NAME');
-    console.log(name + ' version: ' + manifest.version);
+        jsonParseSafe(xhr.responseText);
+    if (manifest) {
+      var name = chrome.i18n.getMessage('PRODUCT_NAME');
+      console.log(name + ' version: ' + manifest.version);
+    } else {
+      console.error('Failed to get product version. Corrupt manifest?');
+    }
   }
   xhr.send(null);
 };
 
 /**
  * If the client is connected, or the host is shared, prompt before closing.
  *
  * @return {?string} The prompt string if a connection is active.
  */
 remoting.promptClose = function() {
@@ skipping 126 matching lines @@
  */
 function getUrlParameters_() {
   var result = {};
   var parts = window.location.search.substring(1).split('&');
   for (var i = 0; i < parts.length; i++) {
     var pair = parts[i].split('=');
     result[pair[0]] = decodeURIComponent(pair[1]);
   }
   return result;
 }
+
+/**
+ * @param {string} jsonString A JSON-encoded string.
+ * @return {*} The decoded object, or undefined if the string cannot be parsed.
+ */
+function jsonParseSafe(jsonString) {
+  try {
+    return JSON.parse(jsonString);
+  } catch (err) {
+    return undefined;
+  }
+}