native theme images for touch UI at 2x scale

TBR=ben@chromium.org
BUG=123162
TEST=none

Review URL: https://chromiumcodereview.appspot.com/10383126

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@136576 0039d316-1c4b-4281-b951-d872f2087c98
34 files changed