Accessibility: chrome://history keyboarding issues.

Apply aria-haspopup attribute to actions buttons.

BUG=320753
TEST=ctrl+alt+z, tab to actions button and hear "action pop-up button".
R=xiyuan@chromium.org

Review URL: https://codereview.chromium.org/130093003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243929 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/history/history.js

@@ -231,6 +231,7 @@ Visit.prototype.getResultDOM = function(propertyBag) {
     dropDown.value = 'Open action menu';
     dropDown.title = loadTimeData.getString('actionMenuDescription');
     dropDown.setAttribute('menu', '#action-menu');
+    dropDown.setAttribute('aria-haspopup', 'true');
     cr.ui.decorate(dropDown, MenuButton);
 
     dropDown.addEventListener('mousedown', setActiveVisit);