Fix/hack operator = to not leak refcounted objects

Agreed that this may be temporary.
Some (many?) of these fields are going away in current or upcoming CLs.
This doesn't seem to cause a bench regression on Linux NULLGPU.

[TomH, 2012-05-31 13:51:01]

As discussed.

[bsalomon, 2012-05-31 14:04:28]

Mostly LGTM

http://codereview.appspot.com/6262049/diff/1/include/gpu/GrSamplerState.h
File include/gpu/GrSamplerState.h (right):

http://codereview.appspot.com/6262049/diff/1/include/gpu/GrSamplerState.h#new...
include/gpu/GrSamplerState.h:144: //memcpy(this, &s, sizeof(GrSamplerState));
Let's just delete this code, we're not going back.

http://codereview.appspot.com/6262049/diff/1/include/gpu/GrSamplerState.h#new...
include/gpu/GrSamplerState.h:158: if (fFilter >= kConvolution_Filter) {
OK, but the morphology code doesn't use the kernel, just the width. (But who
cares, this will be gone soon)

[TomH, 2012-05-31 14:23:58]

Nits done, committed in r4092.