Begin introducing some of the initial pieces for ChromeVox next commands.

chrome/browser/resources/chromeos/chromevox2/cvox2/background/background.js

 // Copyright 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.
 
 /**
  * @fileoverview The entry point for all ChromeVox2 related code for the
  * background page.
  */
 
 goog.provide('cvox2.Background');
 goog.provide('cvox2.global');
 
 /** Classic Chrome accessibility API. */
 cvox2.global.accessibility =
     chrome.accessibilityPrivate || chrome.experimental.accessibility;
 
 /**
  * ChromeVox2 background page.
  */
 cvox2.Background = function() {
+  /**
+   * A list of site substring patterns to use with ChromeVox next. Keep these
+   * strings relatively specific.
+   * @type {!Array.<string>}
+   */
+  this.whitelist_ = ['http://www.chromevox.com/', 'chromevox_next_test'];
+
   // Only needed with unmerged ChromeVox classic loaded before.
+  // TODO(dtseng): Refactor all tabs handlers out of
+  // accessibility_api_handler.js.
   cvox2.global.accessibility.setAccessibilityEnabled(false);
 
   // Register listeners for ...
   // Desktop.
   chrome.automation.getDesktop(this.onGotTree.bind(this));
 
   // Tabs.
   chrome.tabs.onUpdated.addListener(this.onTabUpdated.bind(this));
-
-  // Keyboard events (currently Messages from content script).
-  chrome.extension.onConnect.addListener(this.onConnect.bind(this));
 };
 
 cvox2.Background.prototype = {
   /**
-   * ID of the port used to communicate between content script and background
-   * page.
-   * @const {string}
+   * Handles chrome.tabs.onUpdated.
+   * @param {number} tabId
+   * @param {Object} changeInfo
    */
-  PORT_ID: 'chromevox2',
+  onTabUpdated: function(tabId, changeInfo) {
+    chrome.tabs.get(tabId, function(tab) {
+      if (!tab.url || tab.status == 'loading')
+        return;
 
-  /**
-   * Handles chrome.extension.onConnect.
-   * @param {Object} port The port.
-   */
-  onConnect: function(port) {
-    if (port.name != this.PORT_ID)
-      return;
-    port.onMessage.addListener(this.onMessage.bind(this));
+      if (!this.isWhitelisted_(tab.url)) {
+        chrome.commands.onCommand.removeListener(this.onGotCommand);
+        return;
+      }
+
+      if (!chrome.commands.onCommand.hasListener(this.onGotCommand))
+        chrome.commands.onCommand.addListener(this.onGotCommand.bind(this));
+
+      this.disableClassicChromeVox_(tab.id);
+
+      chrome.automation.getTree(this.onGotTree.bind(this));
+    }.bind(this));
   },
 
   /**
-   * Dispatches messages to specific handlers.
-   * @param {Object} message The message.
-   */
-  onMessage: function(message) {
-    if (message.keyDown)
-      this.onKeyDown(message);
-  },
-
-  /**
-   * Handles key down messages from the content script.
-   * @param {Object} message The key down message.
-   */
-  onKeyDown: function(message) {
-    // TODO(dtseng): Implement.
-  },
-
-  /**
-   * Handles chrome.tabs.onUpdate.
-   * @param {number} tabId The tab id.
-   * @param {Object.<string, (string|boolean)>} changeInfo Information about
-   * the updated tab.
-   */
-  onTabUpdated: function(tabId, changeInfo) {
-    chrome.automation.getTree(this.onGotTree.bind(this));
-  },
-
-  /**
    * Handles all setup once a new automation tree appears.
    * @param {AutomationTree} tree The new automation tree.
    */
   onGotTree: function(root) {
     // Register all automation event listeners.
     root.addEventListener(chrome.automation.EventType.focus,
                           this.onAutomationEvent.bind(this),
                           true);
   },
 
   /**
    * A generic handler for all desktop automation events.
    * @param {AutomationEvent} evt The event.
    */
   onAutomationEvent: function(evt) {
     var output = evt.target.attributes.name + ' ' + evt.target.role;
-    cvox.ChromeVox.tts.speak(output);
+    cvox.ChromeVox.tts.speak(output, cvox.AbstractTts.QUEUE_MODE_FLUSH);
     cvox.ChromeVox.braille.write(cvox.NavBraille.fromText(output));
+  },
+
+  /**
+   * Handles chrome.commands.onCommand.
+   * @param {string} command
+   */
+  onGotCommand: function(command) {
+  },
+
+  /**
+   * @private
+   * @param {string} url
+   * @return {boolean} Whether the given |url| is whitelisted.
+   */
+  isWhitelisted_: function(url) {
+    return this.whitelist_.some(function(item) {
+      return url.indexOf(item) != -1;
+    });
+  },
+
+  /**
+   * Disables classic ChromeVox.
+   * @param {number} tabId The tab where ChromeVox classic is running.
+   */
+  disableClassicChromeVox_: function(tabId) {
+    chrome.tabs.executeScript(
+          tabId,
+          {'code': 'try { window.disableChromeVox(); } catch(e) { }\n',
+           'allFrames': true});
+
   }
 };
 
 /** @type {cvox2.Background} */
 cvox2.global.backgroundObj = new cvox2.Background();