[Boundary interfaces] Add utility methods for support library boundary
am: 7b527a9a1c

Change-Id: I209d647146ec973a5c9afa90737440b2a16cac8c
tree: 1c764c01c6c0bee2e5937f81a9706c19343a4e2d
  1. src/
  2. BUILD.gn
  3. DEPS