Remove another incorrect isAcceleratedCompositingActiveCheck

R=dpranke@chromium.org
BUG=397321

Review URL: https://codereview.chromium.org/599723003

git-svn-id: svn://svn.chromium.org/blink/trunk@182858 bbb929c8-8fbe-4397-9dbb-9b2b20218538