Remove unuseful compositing layout tests

Blink doesn't support a tile cache, so these tests can be removed.
Additionally, huge/tiny layers aren't really testing anything in Blink
anymore and are already adequately tested via compositor unit tests and
pixel tests.

R=jamesr@chromium.org
BUG=none

Review URL: https://codereview.chromium.org/78233005

git-svn-id: svn://svn.chromium.org/blink/trunk@162450 bbb929c8-8fbe-4397-9dbb-9b2b20218538