Parse meta tag that disables ChromeVox content script and forces compat mode.

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

Index: chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
diff --git a/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js b/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
index 5c5b4dfcd0a3c978021d6a122f9aa5eaa68e0f03..e3fab5d3202c9ed6a52cf17b1e2338eebc17d797 100644
--- a/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
+++ b/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
@@ -51,6 +51,14 @@ Background = function() {
   this.whitelist_ = ['chromevox_next_test'];
 
   /**
+   * A list of site substring patterns to blacklist ChromeVox Classic,
+   * putting ChromeVox into Compat mode.
+   * @type {!Array<string>}
+   * @private
+   */
+  this.classicBlacklist_ = [];
+
+  /**
    * Regular expression for blacklisting classic.
    * @type {RegExp}
    * @private
@@ -1002,7 +1010,11 @@ Background.prototype = {
    * @private
    */
   isBlacklistedForClassic_: function(url) {
-    return this.classicBlacklistRegExp_.test(url);
+    if (this.classicBlacklistRegExp_.test(url))
+      return true;
+    return this.classicBlacklist_.some(function(item) {
+      return url.indexOf(item) != -1;
+    });
   },
 
   /**
@@ -1075,6 +1087,11 @@ Background.prototype = {
             target: 'next',
             isClassicEnabled: isClassicEnabled
           });
+        } else if (action == 'enableCompatForUrl') {
+          var url = msg['url'];
+          this.classicBlacklist_.push(url);

[David Tseng, 2016/06/15 22:50:17]

Should be a dictionary/set since we don't want dups.

[dmazzoni, 2016/06/16 20:00:06]

Done.

+          if (this.currentRange_ && this.currentRange_.start.node)
+            this.refreshMode(this.currentRange_.start.node);
         } else if (action == 'onCommand') {
           this.onGotCommand(msg['command']);
         } else if (action == 'flushNextUtterance') {