Add scale and skew to C canvas API

Add scale and skew to C canvas API

R=reed@chromium.org
BUG=skia:

Committed: https://skia.googlesource.com/skia/+/2fc6ea62ce61c3a2b2d9b74a3fbe6b388b5d7558

[reed1, 2014-12-01 20:25:09]

reed@google.com changed reviewers:
+ reed@google.com

[reed1, 2014-12-01 20:25:09]

https://codereview.chromium.org/762493005/diff/1/include/c/sk_canvas.h
File include/c/sk_canvas.h (right):

https://codereview.chromium.org/762493005/diff/1/include/c/sk_canvas.h#newcode24
include/c/sk_canvas.h:24: void sk_canvas_rotate(sk_canvas_t*, float degrees);
I've always felt a little bad about choosing degrees instead of radians. Perhaps
now is a good time to change our default to radians, and perhaps add a helper
(or not) for degress, like sk_canvas_rotate_degrees(...).

[abarth-chromium, 2014-12-01 21:31:54]

Done.  I've made the API explicit about whether it's in degrees or radians and
added both versions.

[reed1, 2014-12-01 21:39:39]

lgtm

[abarth-chromium, 2014-12-01 21:54:02]

The CQ bit was checked by abarth@chromium.org

[commit-bot: I haz the power, 2014-12-01 21:54:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/762493005/20001

[commit-bot: I haz the power, 2014-12-01 22:04:07]

Committed patchset #2 (id:20001) as
https://skia.googlesource.com/skia/+/2fc6ea62ce61c3a2b2d9b74a3fbe6b388b5d7558