cc: Make scroll compensation take integer snapping into account

Scroll layers are snapped to integer coordinates, but fixed position
layers that compensated for that scroll weren't taking that into
consideration.

R=danakj@chromium.org
BUG=309179

Review URL: https://codereview.chromium.org/41603002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230988 0039d316-1c4b-4281-b951-d872f2087c98
Roll Linux reference build to official build 31.0.1650.34 (trunk r224845, branch r230433)

BUG=302065

Review URL: https://codereview.chromium.org/42153003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230989 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230990 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230989
SVN changes up to revision 230990