Revert "Revert "Removing ref counting from GrXPFactory.""

This reverts commit 003312a211e65f35e402d6fe80a32e23d4c94ac4.

Change-Id: Ib41065e5c356d1dd99e70fa10611ac6756c2b79d
Reviewed-on: https://skia-review.googlesource.com/6803
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/include/gpu/effects/GrCustomXfermode.h b/include/gpu/effects/GrCustomXfermode.h
index a8c868e..54309dd 100644
--- a/include/gpu/effects/GrCustomXfermode.h
+++ b/include/gpu/effects/GrCustomXfermode.h
@@ -20,7 +20,7 @@
  */
 namespace GrCustomXfermode {
     bool IsSupportedMode(SkBlendMode mode);
-    sk_sp<GrXPFactory> MakeXPFactory(SkBlendMode mode);
+    const GrXPFactory* Get(SkBlendMode mode);
 };
 
 #endif