Revert of Remove platform specific expectations for http/tests/xmlhttprequest/origin-exact-matching tests (patchset #1 id:1 of https://codereview.chromium.org/641603005/)

Reason for revert:
The tests now fail on Mac

http://test-results.appspot.com/dashboards/flakiness_dashboard.html#master=ChromiumWebkit&tests=http/tests/xmlhttprequest/origin-exact-matching/22.html,http/tests/xmlhttprequest/origin-exact-matching/27.html,http/tests/xmlhttprequest/origin-exact-matching/28.html,http/tests/xmlhttprequest/origin-exact-matching/29.html,http/tests/xmlhttprequest/origin-exact-matching/30.html,http/tests/xmlhttprequest/origin-exact-matching/36.html

Original issue's description:
> Remove platform specific expectations for http/tests/xmlhttprequest/origin-exact-matching tests
> 
> We have some platform specific expectations for some of
> http/tests/xmlhttprequest/origin-exact-matching layout tests
> for mountainlion.
> 
> They're identical to general expectations.
> 
> R=sigbjornf
> BUG=344294
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=184649

TBR=sigbjornf@opera.com,tyoshino@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=344294

Review URL: https://codereview.chromium.org/681003003

git-svn-id: svn://svn.chromium.org/blink/trunk@184656 bbb929c8-8fbe-4397-9dbb-9b2b20218538