Make bookmark bar more amenable to dark themes.
Make bookmark bar more amenable to dark themes.

- Explicitly set button text color.
- Set background of drag widget.

BUG=none
TEST=use a dark system theme, make sure everything looks reasonable.

Review URL: http://codereview.chromium.org/118097

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@17374 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser