Try out refFoo pattern on GrRenderTargetContext

Change-Id: Ifae5618f30c2202b9083f479b58556709ff6126a
Reviewed-on: https://skia-review.googlesource.com/6990
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/src/effects/SkDisplacementMapEffect.cpp b/src/effects/SkDisplacementMapEffect.cpp
index 04b9b4f..28483bd 100644
--- a/src/effects/SkDisplacementMapEffect.cpp
+++ b/src/effects/SkDisplacementMapEffect.cpp
@@ -376,7 +376,7 @@
                                             SkIRect::MakeWH(bounds.width(), bounds.height()),
                                             kNeedNewImageUniqueID_SpecialImage,
                                             sk_ref_sp(renderTargetContext->asDeferredTexture()),
-                                            sk_ref_sp(renderTargetContext->getColorSpace()));
+                                            renderTargetContext->refColorSpace());
     }
 #endif