move colorshader into its own .cpp, add color4f variant

include/core/SkShader.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkShader_DEFINED
 #define SkShader_DEFINED
 
 #include "SkBitmap.h"
 #include "SkFlattenable.h"
 #include "SkImageInfo.h"
 #include "SkMask.h"
 #include "SkMatrix.h"
 #include "SkPaint.h"
 #include "../gpu/GrColor.h"
 
 class SkColorFilter;
+class SkColorSpace;
 class SkPath;
 class SkPicture;
 class SkXfermode;
 class GrContext;
 class GrFragmentProcessor;
 
 /** \class SkShader
  *
  *  Shaders specify the source color(s) for what is being drawn. If a paint
  *  has no shader, then the paint's color is used. If the paint has a
@@ skipping 338 matching lines @@
      *  Call this to create a new "empty" shader, that will not draw anything.
      */
     static sk_sp<SkShader> MakeEmptyShader();
 
     /**
      *  Call this to create a new shader that just draws the specified color. This should always
      *  draw the same as a paint with this color (and no shader).
      */
     static sk_sp<SkShader> MakeColorShader(SkColor);
 
+    /**
+     *  Create a shader that draws the specified color (in the specified colorspace).
+     *
+     *  This works around the limitation that SkPaint::setColor() only takes byte values, and does
+     *  not support specific colorspaces.
+     */
+    static sk_sp<SkShader> MakeColorShader(const SkColor4f&, sk_sp<SkColorSpace>);
+
     static sk_sp<SkShader> MakeComposeShader(sk_sp<SkShader> dst, sk_sp<SkShader> src,
                                              SkXfermode::Mode);
 
 #ifdef SK_SUPPORT_LEGACY_CREATESHADER_PTR
     static SkShader* CreateEmptyShader() { return MakeEmptyShader().release(); }
     static SkShader* CreateColorShader(SkColor c) { return MakeColorShader(c).release(); }
     static SkShader* CreateBitmapShader(const SkBitmap& src, TileMode tmx, TileMode tmy,
                                         const SkMatrix* localMatrix = nullptr) {
         return MakeBitmapShader(src, tmx, tmy, localMatrix).release();
     }
@@ skipping 101 matching lines @@
     SkMatrix fLocalMatrix;
 
     // So the SkLocalMatrixShader can whack fLocalMatrix in its SkReadBuffer constructor.
     friend class SkLocalMatrixShader;
     friend class SkBitmapProcShader;    // for computeTotalInverse()
 
     typedef SkFlattenable INHERITED;
 };
 
 #endif