web-ui settings: Explicitly set preferences for sans-serif font and minimum logical font size.

BUG=73842
TEST=Verify that changing fonts and minimum font size results in correct preferences set in the 'Preferences' file.
Review URL: http://codereview.chromium.org/6577029

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@76141 0039d316-1c4b-4281-b951-d872f2087c98
5 files changed