Mac: Fix missing font-smoothing in address bar when running with CoreAnimation.

Even though -isOpaque is NO due to rounded corners, we know that the text
will be drawn on top of an opaque area, therefore it is safe to enable
font smoothing.

BUG=349605

Review URL: https://codereview.chromium.org/189483002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255583 0039d316-1c4b-4281-b951-d872f2087c98
Follow ARIA spec guidelines for role=button with aria-pressed.

BUG=349626

Review URL: https://codereview.chromium.org/184103036

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255584 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255584