Unrestrict version of PolymerElements/iron-list and update it

chrome/test/data/webui/md_history/md_history_browsertest.js

Index: chrome/test/data/webui/md_history/md_history_browsertest.js
diff --git a/chrome/test/data/webui/md_history/md_history_browsertest.js b/chrome/test/data/webui/md_history/md_history_browsertest.js
index 1c4ea3e5106fc9d6a42bbf92b1e0ab3daa072682..bb6c67632ada4fc1a1c5b515d38c0f579fe3747e 100644
--- a/chrome/test/data/webui/md_history/md_history_browsertest.js
+++ b/chrome/test/data/webui/md_history/md_history_browsertest.js
@@ -22,6 +22,9 @@ MaterialHistoryBrowserTest.prototype = {
 
   commandLineSwitches: [{switchName: 'enable-md-history'}],
 
+  /** @override */
+  runAccessibilityChecks: false,

[Dan Beam, 2016/02/09 04:27:59]

this is the fix to allow us to use newer iron-list

the accessibility audit goes through the DOM calling .focus() a ton on tearDown

this is probably not the best idea for things that take actions based on 'focus'
events (especially in capturing phase), like iron-list does

/cc aboxhall and egarciad

+
   extraLibraries: PolymerTest.getLibraries(ROOT_PATH).concat([
     'test_util.js',
     'history_card_manager_test.js',