Set scissor to clip bounding box when using GrConvexPolyEffect

Set scissor to clip bounding box when using GrConvexPolyEffect

BUG=skia:2051
Committed: http://code.google.com/p/skia/source/detail?r=13361

[bsalomon, 2014-02-06 22:16:01]

This recovers the perf on the N10.

https://codereview.chromium.org/156843005/diff/1/src/gpu/GrClipMaskManager.cpp
File src/gpu/GrClipMaskManager.cpp (right):

https://codereview.chromium.org/156843005/diff/1/src/gpu/GrClipMaskManager.cp...
src/gpu/GrClipMaskManager.cpp:177: SkIRect
scissorSpaceIBounds(clipSpaceIBounds);
It turns out we were already doing this in the stencil mask case.

This reminds me that the path is not always in device space due to save layer
offsets. I'll prepare another CL with a test and fix.

[robertphillips, 2014-02-07 13:42:10]

lgtm

https://codereview.chromium.org/156843005/diff/1/src/gpu/GrClipMaskManager.cpp
File src/gpu/GrClipMaskManager.cpp (right):

https://codereview.chromium.org/156843005/diff/1/src/gpu/GrClipMaskManager.cp...
src/gpu/GrClipMaskManager.cpp:177: SkIRect
scissorSpaceIBounds(clipSpaceIBounds);
That's a better answer then them analyzing our stencil buffer usage.

[bsalomon, 2014-02-07 13:53:04]

The CQ bit was checked by bsalomon@google.com

[commit-bot: I haz the power, 2014-02-07 13:53:15]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/bsalomon@google.com/156843005/1

[commit-bot: I haz the power, 2014-02-07 14:04:50]

Change committed as 13361