Remove GrEffect::CreateEffectRef and GrEffect::AutoEffectRef.

R=robertphillips@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/371103003
diff --git a/src/effects/SkAlphaThresholdFilter.cpp b/src/effects/SkAlphaThresholdFilter.cpp
index 0bc906d..b375c88 100644
--- a/src/effects/SkAlphaThresholdFilter.cpp
+++ b/src/effects/SkAlphaThresholdFilter.cpp
@@ -60,11 +60,10 @@
                                GrTexture* maskTexture,
                                float innerThreshold,
                                float outerThreshold) {
-        AutoEffectUnref effect(SkNEW_ARGS(AlphaThresholdEffect, (texture,
-                                                                 maskTexture,
-                                                                 innerThreshold,
-                                                                 outerThreshold)));
-        return CreateEffectRef(effect);
+        return SkNEW_ARGS(AlphaThresholdEffect, (texture,
+                                                 maskTexture,
+                                                 innerThreshold,
+                                                 outerThreshold));
     }
 
     virtual ~AlphaThresholdEffect() {};