Clean-up: Replaces gfx::Font with gfx::FontList in ash/.

As part of effort to support multiple fonts, this CL changes methods which are now taking gfx::Font so they will take gfx::FontList instead.

See https://docs.google.com/a/chromium.org/document/d/1D_25fp9B8b9aZJORfAjDIFq61NWvUquZ5xmKH-VcC4k/view

BUG=265485
TEST=Run unit_tests, ui_unittests, views_unittests, ash_unittests.

Review URL: https://codereview.chromium.org/110953006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242535 0039d316-1c4b-4281-b951-d872f2087c98
Add transparent omnibox images with combined border/shadow.

This is in preparation for a later change that switches to
drawing the omnibox border and shadow on top of the omnibox
contents.

BUG=233364
TBR=pkasting@chromium.org,oshima@chromium.org

Review URL: https://codereview.chromium.org/94093012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242536 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242536