Rebaseline a couple of constructor tests due to the v8 roll in chromium r26751

Also rebaseline a compositing test where the image diff changed subtly.

TBR=loislo
BUG=

Review URL: https://codereview.chromium.org/261163002

git-svn-id: svn://svn.chromium.org/blink/trunk@173219 bbb929c8-8fbe-4397-9dbb-9b2b20218538