extend modecolorfilter to 4f

include/core/SkColor.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 SkColor_DEFINED
 #define SkColor_DEFINED
 
@@ skipping 174 matching lines @@
     uint64_t toF16() const; // 4 float16 values packed into uint64_t
     static SkPM4f FromF16(const uint16_t[4]);
 
 #ifdef SK_DEBUG
     void assertIsUnit() const;
 #else
     void assertIsUnit() const {}
 #endif
 };
 
+typedef SkPM4f (*SkXfermodeProc4f)(const SkPM4f& src, const SkPM4f& dst);
+
 /*
  *  The float values are 0...1 unpremultiplied
  */
 struct SkColor4f {
     float fA;
     float fR;
     float fG;
     float fB;
 
     bool operator==(const SkColor4f& other) const {
@@ skipping 10 matching lines @@
     static SkColor4f FromColor(SkColor);
 
     SkColor4f pin() const {
         return Pin(fA, fR, fG, fB);
     }
 
     SkPM4f premul() const;
 };
 
 #endif