Revert of The name attribute can be from contents for listitem role (patchset #1 id:1 of https://codereview.chromium.org/696953002/)

Reason for revert:
This seems breaking AccessibilityAriaList in content_browsertests on Mac.
http://build.chromium.org/p/chromium.webkit/builders/Mac10.6%20Tests/builds/27219
http://test-results.appspot.com/dashboards/flakiness_dashboard.html#master=chromium.webkit&testType=content_browsertests&tests=DumpAccessibilityTreeTest.AccessibilityAriaList


Original issue's description:
> The name attribute can be from contents for listitem role
> according to http://www.w3.org/WAI/PF/aria/roles#listitem.
> 
> BUG=347865
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=184795

TBR=dmazzoni@chromium.org,je_julie.kim@samsung.com
NOTREECHECKS=true
NOTRY=true
BUG=347865

Review URL: https://codereview.chromium.org/703473002

git-svn-id: svn://svn.chromium.org/blink/trunk@184802 bbb929c8-8fbe-4397-9dbb-9b2b20218538