Start building HarfBuzz+Skia example

(prevent bitrot in example code)

tools/using_skia_and_harfbuzz.cpp was written by aam@:
  https://github.com/aam/skiaex

update HarfBuzz to latest release: 1.2.7

BUG=skia:4742
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1940393002

Review-Url: https://codereview.chromium.org/1940393002
11 files changed