Remove old SkGaussianEdgeShader code

include/effects/SkGaussianEdgeShader.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkGaussianEdgeShader_DEFINED
 #define SkGaussianEdgeShader_DEFINED
 
 #include "SkShader.h"
 
 class SK_API SkGaussianEdgeShader {
 public:
     /** Returns a shader that applies a Gaussian blur depending on distance to the edge
     * Currently this is only useable with Circle and RRect shapes on the GPU backend.
     * Raster will draw nothing.
     */
-    static sk_sp<SkShader> Make(bool largerBlur = true);
+    static sk_sp<SkShader> Make();
 
     SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
 
 private:
     SkGaussianEdgeShader(); // can't be instantiated
 };
 
 #endif