Implement edge AA for concave polys in the tesselated path renderer.

Review URL:  http://codereview.appspot.com/4571072/



git-svn-id: http://skia.googlecode.com/svn/trunk@1600 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/include/GrDrawTarget.h b/gpu/include/GrDrawTarget.h
index d8d0498..d576d80 100644
--- a/gpu/include/GrDrawTarget.h
+++ b/gpu/include/GrDrawTarget.h
@@ -89,6 +89,10 @@
         kNoColorWrites_StateBit = 0x08, //<! If set it disables writing colors.
                                         //   Useful while performing stencil
                                         //   ops.
+        kEdgeAAConcave_StateBit =  0x10,//<! If set, edge AA will test edge
+                                        //   pairs for convexity while 
+                                        //   rasterizing.  Set this if the
+                                        //   source polygon is non-convex.
 
         // subclass may use additional bits internally
         kDummyStateBit,