Reland #4: Ensure WebView notifies desktop automation on creation,

chrome/browser/resources/chromeos/chromevox/testing/chromevox_next_e2e_test_base.js

Index: chrome/browser/resources/chromeos/chromevox/testing/chromevox_next_e2e_test_base.js
diff --git a/chrome/browser/resources/chromeos/chromevox/testing/chromevox_next_e2e_test_base.js b/chrome/browser/resources/chromeos/chromevox/testing/chromevox_next_e2e_test_base.js
index e432a998de5f9d711f04ff24f136c4ef8509eeee..5eebf0b0085f268dd24e6e3ad05d4f6ac94142c6 100644
--- a/chrome/browser/resources/chromeos/chromevox/testing/chromevox_next_e2e_test_base.js
+++ b/chrome/browser/resources/chromeos/chromevox/testing/chromevox_next_e2e_test_base.js
@@ -29,11 +29,24 @@ ChromeVoxNextE2ETest.prototype = {
     GEN('#include "base/command_line.h"');
   },
 
-  runWithAutomation: function(doc, callback) {
-    this.runWithDocument(doc, function() {
-      chrome.automation.getTree(function(root) {
-        callback(root);
-      }.bind(this));
+  /**
+   * Launches a new tab with the given document, and runs callback when a load
+   * complete fires.
+   * @param {function() : void} doc Snippet wrapped inside of a function.
+   * @param {function()} opt_callback Called once the document is ready.
+   */
+  runWithLoadedTree: function(doc, callback) {
+    chrome.automation.getDesktop(function(r) {
+      function callbackInternal(evt) {
+        if (!evt.target.attributes.url ||
+            evt.target.attributes.url.indexOf('test') == -1)
+          return;
+
+        r.removeEventListener(callbackInternal);
+        callback(evt.target);
+      }
+      r.addEventListener('loadComplete', callbackInternal, true);
+      this.runWithTab(doc);
     }.bind(this));
   }
 };