Free cached AA clip mask when create hard/stencil clip mask

Release the cached AA clip mask when a stencil clip is requested. Note that this only clears the current save/restore state's cached clip mask. Those higher up the stack remain unchanged.

This CL also addresses a resource freeing issue. With the addition of the AACache, the GPU could hold on to scratch textures after the freeing of the texture cache.

These two issues are somewhat related in that the cache clearing change hides the resource freeing issue so I wanted to fix the latter before it could be forgotten.

[bsalomon, 2012-05-17 00:13:49]

LGTM

http://codereview.appspot.com/6214050/diff/1/src/gpu/GrClipMaskManager.cpp
File src/gpu/GrClipMaskManager.cpp (right):

http://codereview.appspot.com/6214050/diff/1/src/gpu/GrClipMaskManager.cpp#ne...
src/gpu/GrClipMaskManager.cpp:130: // AA cache.
This comment refers to a perf not correctness issue, right?

[robertphillips, 2012-05-17 12:01:27]

committed as r3983

http://codereview.appspot.com/6214050/diff/1/src/gpu/GrClipMaskManager.cpp
File src/gpu/GrClipMaskManager.cpp (right):

http://codereview.appspot.com/6214050/diff/1/src/gpu/GrClipMaskManager.cpp#ne...
src/gpu/GrClipMaskManager.cpp:130: // AA cache.
Correct - the utility draws will clear the cache when we may not want them to. I
hope to add a system to the cache that will store the clip stacks and detect
unnecessary cache misses.