SkColorSpaceXformer: Preserve local matrix on shaders

Also, do not drop unknown shaders.

Fixes cts tests.

b/37161109
b/37237678

Bug: skia:
Change-Id: I0fd817a4d6461ede0ccdcb8f3cccb255b646b864
Reviewed-on: https://skia-review.googlesource.com/13246
Commit-Queue: Matt Sarett <msarett@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
1 file changed