GitLab

Add some tests for FontRenderParams's interactions with
Fontconfig, which is used on desktop Linux and Chrome OS.

Also re-add platform_font_pango_unittest.cc for gn.

BUG=125235

Review URL: https://codereview.chromium.org/394963002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283969 0039d316-1c4b-4281-b951-d872f2087c98