Initial support for Ranges over automation nodes (used to track ChromeVox focus).

chrome/browser/resources/chromeos/chromevox/common/chrome_extension_externs.js

Index: chrome/browser/resources/chromeos/chromevox/common/chrome_extension_externs.js
diff --git a/chrome/browser/resources/chromeos/chromevox/common/chrome_extension_externs.js b/chrome/browser/resources/chromeos/chromevox/common/chrome_extension_externs.js
index 67dff9da2eafffd339d8ab6ad8da3e98e93967a2..6f532a96ac2d02a0bbfd915c340d4631b00699b5 100644
--- a/chrome/browser/resources/chromeos/chromevox/common/chrome_extension_externs.js
+++ b/chrome/browser/resources/chromeos/chromevox/common/chrome_extension_externs.js
@@ -1240,6 +1240,12 @@ chrome.automation.AutomationNode.prototype.attributes;
 
 
 /**
+ * @type {!chrome.automation.AutomationNode}
+ */
+chrome.automation.AutomationNode.prototype.root;
+
+
+/**
  * @return {chrome.automation.AutomationNode}
  */
 chrome.automation.AutomationNode.prototype.firstChild = function() {};
@@ -1299,6 +1305,9 @@ chrome.automation.AutomationNode.prototype.removeEventListener =
     function(eventType, callback, capture) {};
 
 
+chrome.automation.AutomationNode.prototype.focus = function() {};
+
+
 /**
  * @param {function(chrome.automation.AutomationNode)} callback
  */