cc: Fix hit-testing in zero-opacity layers.

If a layer that accepts touch or wheel events, but the layer (or one of its
ancestor layers) has zero opacity, then make sure the layer hit-tests correctly.

BUG=295295
R=enne@chromium.org, rbyers@google.com

Review URL: https://codereview.chromium.org/26112002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232881 0039d316-1c4b-4281-b951-d872f2087c98
Fix tests that were setting safebrowsing factories without unsetting them.

BUG=313141
R=shess@chromium.org, tburkard@chromium.org

Review URL: https://codereview.chromium.org/55323002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232882 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 232882