Update SrcRectConstraint doc

Update SrcRectConstraint doc. Previous doc never matched the implementation or the c2d spec.

Committed: https://skia.googlesource.com/skia/+/19e82e3b9f6fb5a02fc033121f2047b4d886112e

[bsalomon, 2015-10-23 16:08:49]

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

[bsalomon, 2015-10-23 16:08:49]

1 pixel is only true for bilerp and not for bicubic or mip.


Personally, I think it is unfortunate to frame this around speed rather than
functionality and to have divergent results in the backends. I think there are
cases where filtering extending outside the rectangle is desirable, not just
faster. Also, the c2d spec requires that the filter not be clamped to the
rectangle. But I can live with it.

[bsalomon, 2015-10-23 16:09:57]

The CQ bit was checked by bsalomon@google.com

[commit-bot: I haz the power, 2015-10-23 16:10:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1411103003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1411103003/1

[commit-bot: I haz the power, 2015-10-23 16:10:08]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from valid reviewer(s) till 2015-10-23 22:10 UTC

[reed1, 2015-10-23 16:26:26]

lgtm

[commit-bot: I haz the power, 2015-10-23 16:27:45]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/19e82e3b9f6fb5a02fc033121f2047b4d886112e