Specify bit depth and color space in SkImage::MakeFromPicture()

BUG=skia:

Change-Id: I1d2a2b1f97557fc3e7ca6c2bdad6329f7760dbd2
Reviewed-on: https://skia-review.googlesource.com/6685
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Mike Reed <reed@google.com>
13 files changed