Revert of Refactoring of CPU NormalMap handling out into its own class

src/core/SkNormalSource.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 SkNormalSource_DEFINED
-#define SkNormalSource_DEFINED
-
-#include "SkFlattenable.h"
-
-/** Abstract class that generates or reads in normals for use by SkLightingShader. Not to be
-    used as part of the API yet. Used internally by SkLightingShader.
-*/
-class SK_API SkNormalSource : public SkFlattenable {
-public:
-    virtual ~SkNormalSource() override;
-
-#if SK_SUPPORT_GPU
-    /** Returns a fragment processor that takes no input and outputs a normal (already rotated)
-        as its output color. To be used as a child fragment processor.
-    */
-    virtual sk_sp<GrFragmentProcessor> asFragmentProcessor(
-            GrContext* context,
-            const SkMatrix& viewM,
-            const SkMatrix* localMatrix,
-            SkFilterQuality filterQuality,
-            SkSourceGammaTreatment gammaTreatment) const = 0;
-#endif
-
-    class Provider {
-    public:
-        virtual ~Provider() {};
-
-        /** Called for each span of the object being drawn on the CPU. Your subclass should set
-            the appropriate normals that correspond to the specified device coordinates.
-        */
-        virtual void fillScanLine(int x, int y, SkPoint3 output[], int count) const = 0;
-    };
-
-    /** Returns an instance of 'Provider' that provides normals for the CPU pipeline. The
-        necessary data will be initialized in place at 'storage'.
-    */
-    virtual Provider* asProvider(const SkShader::ContextRec&, void* storage) const = 0;
-
-    /** Amount of memory needed to store a provider object and its dependencies.
-     */
-    virtual size_t providerSize(const SkShader::ContextRec&) const = 0;
-
-    /** Returns a normal source that provides normals sourced from the the normal map argument.
-        Not to be used as part of the API yet. Used internally by SkLightingShader.
-
-        @param  map              a shader that outputs the normal map
-        @param  normRotation     rotation applied to the normal map's normals, in the
-                                 [cos a, sin a] form.
-
-        nullptr will be returned if 'map' is null
-
-        The normal map is currently assumed to be an 8888 image where the normal at a texel
-        is retrieved by:
-            N.x = R-127;
-            N.y = G-127;
-            N.z = B-127;
-            N.normalize();
-        The +Z axis is thus encoded in RGB as (127, 127, 255) while the -Z axis is
-        (127, 127, 0).
-    */
-    static sk_sp<SkNormalSource> MakeFromNormalMap(sk_sp<SkShader> map,
-                                                   const SkVector& normRotation);
-
-    SK_DEFINE_FLATTENABLE_TYPE(SkNormalSource)
-    SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
-};
-
-#endif