check matrix does not have rotation or perspective transformation

check matrix does not have rotation or perspective transformation

When checking whether we need apply AA to a rect for non-msaa target,
simply checking that the mapped rect is integer is not enough.
We need to check whether the transformation matrix has transformations
other than simple translation.

Original-Author: Henry Song <henrysong@samsung.com>;

Committed: https://skia.googlesource.com/skia/+/e638d1c29b2895a4dcf41b5bc8868278192bf819

[derekf, 2014-12-02 20:44:29]

derekf@osg.samsung.com changed reviewers:
+ bsalomon@google.com

[derekf, 2014-12-02 20:44:30]

This cropped up recently when commit 6dc413673 made bitmaps use drawrect to get
anti-aliased edges.  One of the tests (drawbitmapmatrix) didn't look right
because it was errantly disabling AA.

[bsalomon, 2014-12-02 21:36:57]

https://codereview.chromium.org/772953002/diff/1/src/gpu/GrContext.cpp
File src/gpu/GrContext.cpp (right):

https://codereview.chromium.org/772953002/diff/1/src/gpu/GrContext.cpp#newcod...
src/gpu/GrContext.cpp:653: if (!combinedMatrix.rectStaysRect())
style nit: we always use { }.

Otherwise, lgtm

[derekf, 2014-12-02 21:40:32]

The CQ bit was checked by derekf@osg.samsung.com

[commit-bot: I haz the power, 2014-12-02 21:40:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/772953002/20001

[commit-bot: I haz the power, 2014-12-02 21:51:33]

Committed patchset #2 (id:20001) as
https://skia.googlesource.com/skia/+/e638d1c29b2895a4dcf41b5bc8868278192bf819