Adds assets for new scrollbar look on win

BUG=333499
TEST=none
R=oshima@chromium.org

Review URL: https://codereview.chromium.org/141873003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245619 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245619