Replace GrClip with SkClipStack

This CL removes all use of GrClip. A follow on CL will actually remove GrClip & its related classes.

[bsalomon, 2012-07-31 17:55:21]

LGTM

http://codereview.appspot.com/6449070/diff/1/src/gpu/SkGpuDevice.cpp
File src/gpu/SkGpuDevice.cpp (right):

http://codereview.appspot.com/6449070/diff/1/src/gpu/SkGpuDevice.cpp#newcode352
src/gpu/SkGpuDevice.cpp:352: fClipData.fClipStack = canvas->getClipStack();
Do we have a clipstack lifetime issue if the SkCanvas goes away before
GrContext?

[robertphillips, 2012-07-31 19:16:27]

committed as r4865

http://codereview.appspot.com/6449070/diff/1/src/gpu/SkGpuDevice.cpp
File src/gpu/SkGpuDevice.cpp (right):

http://codereview.appspot.com/6449070/diff/1/src/gpu/SkGpuDevice.cpp#newcode352
src/gpu/SkGpuDevice.cpp:352: fClipData.fClipStack = canvas->getClipStack();
I don't think so since 'onDetachFromCanvas' should be called when SkCanvas goes
away. I suppose there could be problems if one directly called rendering methods
on the SkGpuDevice with no SkCanvas attached but I don't think that is a use
case we are considering?