[NaCl SDK AppEngine] Fix PNaCl demos after html5 onpopstate change.

native_client_sdk/src/gonacl_appengine/static/frame.js

 // Copyright (c) 2013 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 examples = [
   {name: 'bullet', text: 'Bullet Physics'},
   {name: 'earth', text: 'Raycasted Earth'},
   {name: 'lua', text: 'Lua Interpreter'},
   {name: 'life', text: 'Game of Life'},
   {name: 'voronoi', text: 'Voronoi Simulation'},
   {name: 'smoothlife', text: 'SmoothLife'},
   {name: 'cube', text: 'Rotating Cube'},
 ];
 var exampleMap = {};  // Created below.
 
-var iframeEl = null;
 var isChrome = /Chrome\/([^\s]+)/.test(navigator.userAgent);
 var isMobile = /Mobi/.test(navigator.userAgent);
 var hasPnacl = navigator.mimeTypes['application/x-pnacl'] !== undefined;
 
 if (isChrome && !isMobile) {
   if (hasPnacl) {
     makeExampleList();
-    window.onpopstate = function(popState) {
-      if (popState.state == null) {
-        updateViewFromLocation();
-      } else {
-        var exampleName = popState.state;
-        loadExample(popState.state);
-      }
+    if (history.state == null) {
+      updateViewFromLocation();
+    }
+
+    window.onpopstate = function(event) {
+      var exampleName = event.state;
+      loadExample(exampleName);
     }
   } else {
     // Older version of Chrome?
     showOldChromeErrorMessage();
   }
 } else {
   // Not Chrome, or is mobile Chrome.
   showNotChromeErrorMessage();
 }
 
@@ skipping 83 matching lines @@
 
 function createExampleIframe(exampleName) {
   createIframe(getExampleUrl(exampleName));
 }
 
 function createHomeIframe() {
   createIframe('/static/home/index.html');
 }
 
 function createIframe(src) {
-  var oldIframeEl = iframeEl;
-
-  iframeEl = document.createElement('iframe');
-  iframeEl.setAttribute('frameborder', '0');
-  iframeEl.setAttribute('width', '100%');
-  iframeEl.setAttribute('height', '100%');
-  iframeEl.src = src;
-  iframeEl.setAttribute('hidden', '');
-  iframeEl.onload = function() {
-    if (oldIframeEl)
-      oldIframeEl.parentNode.removeChild(oldIframeEl);
-    iframeEl.removeAttribute('hidden');
+  var iframeEl = document.querySelector('iframe');
+  if (iframeEl === null) {
+    iframeEl = document.createElement('iframe');
+    iframeEl.setAttribute('frameborder', '0');
+    iframeEl.setAttribute('width', '100%');
+    iframeEl.setAttribute('height', '100%');
+    iframeEl.src = src;
+    document.querySelector('section').appendChild(iframeEl);
+  } else {
+    iframeEl.contentDocument.location.replace(src);
   }
-  document.querySelector('section').appendChild(iframeEl);
 }
 
 function pushState(exampleName) {
   window.history.pushState(exampleName, '', '/demo/' + exampleName);
 }
 
 function replaceState(exampleName) {
   window.history.replaceState(exampleName, '', '/demo/' + exampleName);
 }
 
 function replaceHomeState() {
   window.history.replaceState('home', '', '/demo');
 }
 
 function showOldChromeErrorMessage() {
   document.getElementById('old-chrome').removeAttribute('hidden');
 }
 
 function showNotChromeErrorMessage() {
   document.getElementById('not-chrome').removeAttribute('hidden');
 }