make SkPM4f private

include/core/SkColor.h

Index: include/core/SkColor.h
diff --git a/include/core/SkColor.h b/include/core/SkColor.h
index 101a9bdbed0a4d6a89838cd902d3780a36383ada..a40e5f1f1588eddbe37bad16f5705acb496f7c13 100644
--- a/include/core/SkColor.h
+++ b/include/core/SkColor.h
@@ -160,39 +160,7 @@ typedef SkPMColor (*SkXfermodeProc)(SkPMColor src, SkPMColor dst);
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
-struct SkColor4f;
-
-/*
- *  The float values are 0...1 premultiplied
- */
-struct SkPM4f {
-    enum {
-        A = SK_A32_SHIFT/8,
-        R = SK_R32_SHIFT/8,
-        G = SK_G32_SHIFT/8,
-        B = SK_B32_SHIFT/8,
-    };
-    float fVec[4];
-
-    float a() const { return fVec[A]; }
-
-    SkColor4f unpremul() const;
-
-    static SkPM4f FromPMColor(SkPMColor);
-
-    // half-float routines
-    void toF16(uint16_t[4]) const;
-    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);
+struct SkPM4f;
 
 /*
  *  The float values are 0...1 unpremultiplied