Remove hit-testing-only RSLL entries
As of https://codereview.chromium.org/
266913021/ we no longer hit test
via the RSLL; we walk the tree instead. This means we can remove the
machinery added to allow hidden layers to appear in the RSLL for hit
testing purposes.
This is essentially a revert of https://codereview.chromium.org/
25712004
R=danakj@chromium.org
BUG=None
Review URL: https://codereview.chromium.org/
289973003
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@270742 0039d316-1c4b-4281-b951-d872f2087c98