Fix GrSamplerState::operator=() to take a reference rather than a copy.
Visual review by bsalomon@.



git-svn-id: http://skia.googlecode.com/svn/trunk@4128 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/gpu/GrSamplerState.h b/include/gpu/GrSamplerState.h
index 3cafa45..b1c4852 100644
--- a/include/gpu/GrSamplerState.h
+++ b/include/gpu/GrSamplerState.h
@@ -115,7 +115,7 @@
     }
     bool operator !=(const GrSamplerState& s) const { return !(*this == s); }
 
-    GrSamplerState& operator =(const GrSamplerState s) {
+    GrSamplerState& operator =(const GrSamplerState& s) {
         // memcpy() breaks refcounting
         fWrapX = s.fWrapX;
         fWrapY = s.fWrapY;