Fix the T-Rex easter egg on iOS.

components/neterror/resources/offline.js

 // Copyright (c) 2014 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.
 (function() {
 'use strict';
 /**
  * T-Rex runner.
  * @param {string} outerContainerId Outer containing element id.
  * @param {Object} opt_config
  * @constructor
@@ skipping 274 matching lines @@
    */
   loadImages: function() {
     if (IS_HIDPI) {
       Runner.imageSprite = document.getElementById('offline-resources-2x');
       this.spriteDef = Runner.spriteDefinition.HDPI;
     } else {
       Runner.imageSprite = document.getElementById('offline-resources-1x');
       this.spriteDef = Runner.spriteDefinition.LDPI;
     }
 
-    this.init();
+    if (Runner.imageSprite.complete) {
+      this.init();
+    } else {
+      // If the images are not yet loaded, add a listener.
+      Runner.imageSprite.addEventListener(Runner.events.LOAD,
+          this.init.bind(this));
+    }
   },
 
   /**
    * Load and decode base 64 encoded sounds.
    */
   loadSounds: function() {
     if (!IS_IOS) {
       this.audioContext = new AudioContext();
 
       var resourceTemplate =
@@ skipping 347 matching lines @@
     if (IS_MOBILE && this.activated) {
       e.preventDefault();
     }
 
     if (e.target != this.detailsButton) {
       if (!this.crashed && (Runner.keycodes.JUMP[e.keyCode] ||
            e.type == Runner.events.TOUCHSTART)) {
         if (!this.activated) {
           this.loadSounds();
           this.activated = true;
-          errorPageController.trackEasterEgg();
+          if (window.errorPageController) {
+            errorPageController.trackEasterEgg();
+          }
         }
 
         if (!this.tRex.jumping && !this.tRex.ducking) {
           this.playSound(this.soundFx.BUTTON_PRESS);
           this.tRex.startJump(this.currentSpeed);
         }
       }
 
       if (this.crashed && e.type == Runner.events.TOUCHSTART &&
           e.currentTarget == this.containerEl) {
@@ skipping 2006 matching lines @@
 
   /**
    * Add a new cloud to the horizon.
    */
   addCloud: function() {
     this.clouds.push(new Cloud(this.canvas, this.spritePos.CLOUD,
         this.dimensions.WIDTH));
   }
 };
 })();