sk_sp for Ganesh.

Convert use of GrFragmentProcessor, GrGeometryProcessor, and
GrXPFactory to sk_sp. This clarifies ownership and should
reduce reference count churn by moving ownership.

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2041113004

Review-Url: https://codereview.chromium.org/2041113004
diff --git a/include/gpu/GrContext.h b/include/gpu/GrContext.h
index 4e2546b..f9d06f0 100644
--- a/include/gpu/GrContext.h
+++ b/include/gpu/GrContext.h
@@ -457,9 +457,9 @@
      * of effects that make a readToUPM->writeToPM->readToUPM cycle invariant. Otherwise, they
      * return NULL. They also can perform a swizzle as part of the draw.
      */
-    const GrFragmentProcessor* createPMToUPMEffect(GrTexture*, const GrSwizzle&,
+    sk_sp<GrFragmentProcessor> createPMToUPMEffect(GrTexture*, const GrSwizzle&,
                                                    const SkMatrix&) const;
-    const GrFragmentProcessor* createUPMToPMEffect(GrTexture*, const GrSwizzle&,
+    sk_sp<GrFragmentProcessor> createUPMToPMEffect(GrTexture*, const GrSwizzle&,
                                                    const SkMatrix&) const;
     /** Called before either of the above two functions to determine the appropriate fragment
         processors for conversions. This must be called by readSurfacePixels before a mutex is