HiDPI dropdown arrow for webui

BUG=134372
TEST=Look at search engine dropdown arrow
TBR=avi

Review URL: https://chromiumcodereview.appspot.com/10690003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@144391 0039d316-1c4b-4281-b951-d872f2087c98
4 files changed