4f linear gradient shader blitters

src/effects/gradients/Sk4fGradientBase.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 Sk4fGradientBase_DEFINED
 #define Sk4fGradientBase_DEFINED
 
+#include "Sk4fGradientPriv.h"
 #include "SkColor.h"
 #include "SkGradientShaderPriv.h"
 #include "SkMatrix.h"
 #include "SkNx.h"
 #include "SkPM4f.h"
 #include "SkShader.h"
 #include "SkTArray.h"
 
 class SkGradientShaderBase::
 GradientShaderBase4fContext : public SkShader::Context {
@@ skipping 33 matching lines @@
 
 private:
     using INHERITED = SkShader::Context;
 
     void addMirrorIntervals(const SkGradientShaderBase&,
                             const Sk4f& componentScale, bool reverse);
 
     template<typename DstType, SkShader::TileMode tileMode>
     class TSampler;
 
-    template <typename DstType, bool do_premul>
+    template <typename DstType, ApplyPremul>
     void shadePremulSpan(int x, int y, DstType[], int count) const;
 
-    template <typename DstType, bool do_premul, SkShader::TileMode tileMode>
+    template <typename DstType, ApplyPremul, SkShader::TileMode tileMode>
     void shadeSpanInternal(int x, int y, DstType[], int count) const;
 };
 
 #endif // Sk4fGradientBase_DEFINED