proper handling if SkMatrix::invert failes, addresses hack fix in rev. 3657



git-svn-id: http://skia.googlecode.com/svn/trunk@3679 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/effects/Sk2DPathEffect.h b/include/effects/Sk2DPathEffect.h
index 67e7857..30bbe1a 100644
--- a/include/effects/Sk2DPathEffect.h
+++ b/include/effects/Sk2DPathEffect.h
@@ -48,6 +48,8 @@
 
 private:
     SkMatrix    fMatrix, fInverse;
+    bool        fMatrixIsInvertible;
+
     // illegal
     Sk2DPathEffect(const Sk2DPathEffect&);
     Sk2DPathEffect& operator=(const Sk2DPathEffect&);