Adding TestFontCollection

Change-Id: I43c20616dd842e9ffeaac614c853be4702a819a7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/222104
Commit-Queue: Julia Lavrova <jlavrova@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
9 files changed