Disable unreliable test parts.

Initiator for images loaded from style recalculation is unreliable now.

BUG=155260, 306228
NOTRY=true
TBR=vsevik

Review URL: https://codereview.chromium.org/153043007

git-svn-id: svn://svn.chromium.org/blink/trunk@166994 bbb929c8-8fbe-4397-9dbb-9b2b20218538