Inline CompositingRequirementsUpdater::isRunningAcceleratedTransformAnimation

This function is one line long and has one caller.

Review URL: https://codereview.chromium.org/341303002

git-svn-id: svn://svn.chromium.org/blink/trunk@176661 bbb929c8-8fbe-4397-9dbb-9b2b20218538