Implement onMakeClone(const SkFontArguments& args) in class SkTypeface_fontconfig.

Create FontMgrFontConfigTest.cpp file to test the above function.

Change-Id: I7716355f702af3d6f25574305914f0b82a4147ce
Reviewed-on: https://skia-review.googlesource.com/137133
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
4 files changed