Fix for partially-specified crop rects.

Fix for partially-specified crop rects.

When only the left or top edge of a crop rect is given, the
right and bottom should be computed based on the incoming width
and height, not based on the crop rect's width & height. This
complies more accurately with SVG semantics.

BUG=240827
Committed: https://skia.googlesource.com/skia/+/24d2a7b463d585f9300ceac946431e822531d504

[Stephen White, 2015-07-13 15:46:28]

senorblanco@chromium.org changed reviewers:
+ robertphillips@chromium.org

[Stephen White, 2015-07-13 15:47:28]

Rob: PTAL. Thanks!

(Note: this is a copy of https://codereview.chromium.org/1234873005/ without the
name changes. Those will be done in a followup CL.)

[robertphillips, 2015-07-13 17:10:48]

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

[robertphillips, 2015-07-13 17:10:49]

lgtm

[Stephen White, 2015-07-13 17:19:42]

The CQ bit was checked by senorblanco@chromium.org

[commit-bot: I haz the power, 2015-07-13 17:20:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1232873002/10003

[commit-bot: I haz the power, 2015-07-13 17:27:09]

Committed patchset #2 (id:10003) as
https://skia.googlesource.com/skia/+/24d2a7b463d585f9300ceac946431e822531d504