Disable pushState and the rest of the history API in packaged apps via runtime-enabled features

chrome/test/data/extensions/platform_apps/restrictions/main.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.
 
 var assertEq = chrome.test.assertEq;
 var assertTrue = chrome.test.assertTrue;
 var fail = chrome.test.fail;
 var succeed = chrome.test.succeed;
 
 function assertThrowsError(method, opt_expectedError) {
@@ skipping 26 matching lines @@
     assertThrowsError(function() {document.bgColor;});
     assertThrowsError(function() {document.fgColor;});
     assertThrowsError(function() {document.alinkColor;});
     assertThrowsError(function() {document.linkColor;});
     assertThrowsError(function() {document.vlinkColor;});
 
     succeed();
   },
 
   function testHistory() {
+    // These are replaced by wrappers that throws exceptions.
     assertThrowsError(history.back);
     assertThrowsError(history.forward);
-    assertThrowsError(history.pushState);
-    assertThrowsError(history.replaceState);
     assertThrowsError(function() {history.length;});
-    assertThrowsError(function() {history.state;});
+
+    // These are part of the HTML5 History API that is feature detected, so we
+    // remove them altogether, allowing apps to have fallback behavior.
+    chrome.test.assertFalse('pushState' in history);
+    chrome.test.assertFalse('replaceState' in history);
+    chrome.test.assertFalse('state' in history);
+
     succeed();
   },
 
   function testWindowFind() {
     assertThrowsError(Window.prototype.find);
     assertThrowsError(window.find);
     assertThrowsError(find);
     succeed();
   },
 
@@ skipping 101 matching lines @@
     assertEq('undefined', typeof(chrome.extension));
     succeed();
   },
 
   function testExtensionApis() {
     assertEq('undefined', typeof(chrome.tabs));
     assertEq('undefined', typeof(chrome.windows));
     succeed();
   }
 ]);