[Autofill] A bit of cleanup in autofill_agent.cc

BUG=none
TEST=none
R=estade@chromium.org

Review URL: https://codereview.chromium.org/176213002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253137 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253137
aura: Make Window::HitTest() a private method.

This is the first step towards removing Window::HitTest(), and related methods
from WindowDelegate (and corresponding methods in views::WidgetDelegate). This
is currently used only in a handful of places. This CL replaces those calls
with equivalent code, and makes Window::HitTest() a private method, so that
new code do not use it.

BUG=318879
R=sky@chromium.org

Review URL: https://codereview.chromium.org/178493003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253138 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253138