Adds end-to-end tests for VrShell navigation transitions.

chrome/test/data/android/webvr_instrumentation/resources/navigation_e2e.js

Index: chrome/test/data/android/webvr_instrumentation/resources/navigation_e2e.js
diff --git a/chrome/test/data/android/webvr_instrumentation/resources/navigation_e2e.js b/chrome/test/data/android/webvr_instrumentation/resources/navigation_e2e.js
new file mode 100644
index 0000000000000000000000000000000000000000..3282451282a0a897fd631fdb2948e52a3999f31a
--- /dev/null
+++ b/chrome/test/data/android/webvr_instrumentation/resources/navigation_e2e.js
@@ -0,0 +1,16 @@
+// Copyright 2017 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 setFullscreen(checkbox) {
+  if (checkbox.checked) {
+    document.body.webkitRequestFullScreen();
+  } else {
+    document.webkitCancelFullScreen();
+  }
+}
+function onFullscreenChange() {
+  finishJavaScriptStep();
+}
+document.addEventListener('webkitfullscreenchange', onFullscreenChange, false);
+window.addEventListener('load', finishJavaScriptStep, false);