Preserve GrContext's matrix when calling SkShader::asNewEffect.

Preserve GrContext's matrix when calling SkShader::asNewEffect.

Committed: http://code.google.com/p/skia/source/detail?r=14801

[bsalomon, 2014-05-20 14:29:52]

This is needed to turn off bicubic in the bitmap shader based on the matrix.

[robertphillips, 2014-05-20 14:36:16]

lgtm + questions

https://codereview.chromium.org/298713002/diff/1/src/gpu/SkGr.cpp
File src/gpu/SkGr.cpp (right):

https://codereview.chromium.org/298713002/diff/1/src/gpu/SkGr.cpp#newcode380
src/gpu/SkGr.cpp:380: 
Should this be in GrContext like the other two?

https://codereview.chromium.org/298713002/diff/1/src/gpu/SkGr.cpp#newcode387
src/gpu/SkGr.cpp:387: ~AutoMatrix() {
Don't we usually have a "if (NULL != fContext)" guard?

[bsalomon, 2014-05-20 14:39:46]

On 2014/05/20 14:36:16, robertphillips wrote:
> lgtm + questions
> 
> https://codereview.chromium.org/298713002/diff/1/src/gpu/SkGr.cpp
> File src/gpu/SkGr.cpp (right):
> 
> https://codereview.chromium.org/298713002/diff/1/src/gpu/SkGr.cpp#newcode380
> src/gpu/SkGr.cpp:380: 
> Should this be in GrContext like the other two?

There is an AutoMatrix in GrContext. It doesn't have a mode that just restores
the matrix without also modifying the matrix during the constructor. This is
because we have a GrPaint that must be adjusted when the matrix changes.
GrContext::AutoMatrix adjusts the GrPaint as it sets the new matrix on the
context. This is where we're constructing the GrPaint, though, so it's a special
case.

> 
> https://codereview.chromium.org/298713002/diff/1/src/gpu/SkGr.cpp#newcode387
> src/gpu/SkGr.cpp:387: ~AutoMatrix() {
> Don't we usually have a "if (NULL != fContext)" guard?

Most of the Autos are general purpose, this is only used in this file in one
place where the context can't be NULL. I'll add an assert.

[bsalomon, 2014-05-20 15:00:35]

The CQ bit was checked by bsalomon@google.com

[commit-bot: I haz the power, 2014-05-20 15:00:53]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/bsalomon@google.com/298713002/10001

[commit-bot: I haz the power, 2014-05-20 15:06:31]

Change committed as 14801