virtual/web-animations-css/animations/cross-fade-background-image.html is flaky TIMEOUT

Add a TIMEOUT TestExpectation for this test.

TBR=dstockwell@chromium.org
NOTRY=true
BUG=306967

Review URL: https://codereview.chromium.org/27164004

git-svn-id: svn://svn.chromium.org/blink/trunk@159576 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add some more image tests

fast/images/12-55.html
fast/images/182.html
fast/images/2-comp.html
fast/images/2-dht.html
fast/images/23-55.html

TBR=mikelawther@chromium.org
NOTRY=true
BUG=299835

Review URL: https://codereview.chromium.org/27116006

git-svn-id: svn://svn.chromium.org/blink/trunk@159577 bbb929c8-8fbe-4397-9dbb-9b2b20218538