fix webkitpy tests after r157878

TBR=peter@chromium.org
BUG=289883

Review URL: https://codereview.chromium.org/23498042

git-svn-id: svn://svn.chromium.org/blink/trunk@157881 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Update TestExpectations to reflect new Retina config.

Marking these as 'NeedsManualRebaseline' so that I can do another
pass over them to see if there are any real failures before we
actually create the new baselines.

TBR=ojan@chromium.org
BUG=292886

Review URL: https://codereview.chromium.org/24047008

git-svn-id: svn://svn.chromium.org/blink/trunk@157882 bbb929c8-8fbe-4397-9dbb-9b2b20218538