makeSurface defaults to raster

Rather that returning nullptr for a recording
canvas, return a raster canvas instead.

R=reed@google.com,robertphillips@google.com

Bug: skia:
Change-Id: I211d8ef368b9aec6d14cc72d1652ac6a03f3fa7b
Reviewed-on: https://skia-review.googlesource.com/151666
Commit-Queue: Cary Clark <caryclark@skia.org>
Reviewed-by: Robert Phillips <robertphillips@google.com>
32 files changed