Factory methods for heap-allocated SkPathEffect and SkXfermode objects.

include/effects/SkAvoidXfermode.h

Index: include/effects/SkAvoidXfermode.h
diff --git a/include/effects/SkAvoidXfermode.h b/include/effects/SkAvoidXfermode.h
index afc3fc9d7009e572537d3aa5410bd29a2edb4c84..2fa20b98346781c370af9faaaa256d76053435f4 100644
--- a/include/effects/SkAvoidXfermode.h
+++ b/include/effects/SkAvoidXfermode.h
@@ -37,7 +37,9 @@ public:
                 Tolerance near 0: draw only on colors that are nearly identical to the op-color
                 Tolerance near 255: draw on any colors even remotely similar to the op-color
      */
-    SkAvoidXfermode(SkColor opColor, U8CPU tolerance, Mode mode);
+    static SkAvoidXfermode* Create(SkColor opColor, U8CPU tolerance, Mode mode) {
+        return SkNEW_ARGS(SkAvoidXfermode, (opColor, tolerance, mode));
+    }
 
     // overrides from SkXfermode
     virtual void xfer32(SkPMColor dst[], const SkPMColor src[], int count,
@@ -54,6 +56,11 @@ protected:
     SkAvoidXfermode(SkReadBuffer&);
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
 
+#ifdef SK_SUPPORT_LEGACY_PUBLICEFFECTCONSTRUCTORS
+public:
+#endif
+    SkAvoidXfermode(SkColor opColor, U8CPU tolerance, Mode mode);
+
 private:
     SkColor     fOpColor;
     uint32_t    fDistMul;   // x.14