Remove the compositing/video-page-visiblity test

This test has been effectively disabled for 2 years, and it is testing
video layers to updating textures in a way that we don't even do anymore.

Video layers should be covered by cc_unittests instead.

R=enne
BUG=251973, 231357, 344237

Review URL: https://codereview.chromium.org/252993002

git-svn-id: svn://svn.chromium.org/blink/trunk@172830 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Rebaseline media source tests after WebM duration changes.

http://crrev.com/264708 has landed, so these tests can be fixed
and the expectations removed.

BUG=356805
TEST=layout tests pass

Review URL: https://codereview.chromium.org/260133004

git-svn-id: svn://svn.chromium.org/blink/trunk@172831 bbb929c8-8fbe-4397-9dbb-9b2b20218538