Get viewer running on iOS

Bug: skia:
Change-Id: Ic8b25ca2ecf51cfc190ac01bc9282396905a33b3
Reviewed-on: https://skia-review.googlesource.com/40862
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
8 files changed