Bring accessibility-audit up to date

BUG=162740
NOTRY=true

Review URL: https://codereview.chromium.org/290493004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@271701 0039d316-1c4b-4281-b951-d872f2087c98

chrome/test/data/webui/test_api.js

@@ -142,6 +142,8 @@ var testing = {};
       if (!this.accessibilityAuditConfig_) {
         this.accessibilityAuditConfig_ = new axs.AuditConfiguration();
 
+        this.accessibilityAuditConfig_.showUnsupportedRulesWarning = false;
+
         this.accessibilityAuditConfig_.auditRulesToIgnore = [
             // The "elements with meaningful background image" accessibility
             // audit (AX_IMAGE_01) does not apply, since Chrome doesn't

third_party/accessibility-audit/README.chromium

 Name: Accessibility Audit library, from Accessibility Developer Tools
 Short Name: accessibility-audit
-URL: https://github.com/GoogleChrome/accessibility-developer-tools/
+URL: https://raw.githubusercontent.com/GoogleChrome/accessibility-developer-tools/master/dist/js/axs_testing.js
 Version: 0
-Revision: 3c23a70bf1ef21e494d7ba0ef5622354473f13d0
+Revision: 3d4893b4ecd0eb8f4765e04479213d04b240f3e0
 License: Apache 2.0
 License File: LICENSE
 Security Critical: no