remove experimental treat-skcolor-as-srgb flag

src/core/SkColor.cpp

 /*
  * 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.
  */
 
 #include "SkColor.h"
 #include "SkColorPriv.h"
 #include "SkFixed.h"
 
-bool gTreatSkColorAsSRGB;
-
 SkPMColor SkPreMultiplyARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b) {
     return SkPremultiplyARGBInline(a, r, g, b);
 }
 
 SkPMColor SkPreMultiplyColor(SkColor c) {
     return SkPremultiplyARGBInline(SkColorGetA(c), SkColorGetR(c),
                                    SkColorGetG(c), SkColorGetB(c));
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ skipping 127 matching lines @@
     SkASSERT((c4 >= Sk4f(0)).allTrue() && (c4 <= Sk4f(1)).allTrue());
 }
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 SkColor4f SkColor4f::FromColor(SkColor c) {
     Sk4f value = SkNx_shuffle<2,1,0,3>(SkNx_cast<float>(Sk4b::Load(&c)));
     SkColor4f c4;
     (value * Sk4f(1.0f / 255)).store(&c4);
-    if (gTreatSkColorAsSRGB) {
-        c4.fR = srgb_to_linear(c4.fR);
-        c4.fG = srgb_to_linear(c4.fG);
-        c4.fB = srgb_to_linear(c4.fB);
-    }
+    c4.fR = srgb_to_linear(c4.fR);
+    c4.fG = srgb_to_linear(c4.fG);
+    c4.fB = srgb_to_linear(c4.fB);
     return c4;
 }
 
 SkColor SkColor4f::toSkColor() const {
     SkColor result;
-    Sk4f value = SkNx_shuffle<2, 1, 0, 3>(Sk4f::Load(this->vec()));
+    Sk4f value = Sk4f(linear_to_srgb(fB), linear_to_srgb(fG), linear_to_srgb(fR), fA);
     SkNx_cast<uint8_t>(value * Sk4f(255) + Sk4f(0.5f)).store(&result);
     return result;
 }
 
 SkColor4f SkColor4f::Pin(float r, float g, float b, float a) {
     SkColor4f c4;
     Sk4f::Min(Sk4f::Max(Sk4f(r, g, b, a), Sk4f(0)), Sk4f(1)).store(c4.vec());
     return c4;
 }
 
 SkPM4f SkColor4f::premul() const {
     auto src = Sk4f::Load(this->pin().vec());
     float srcAlpha = src[3];  // need the pinned version of our alpha
     src = src * Sk4f(srcAlpha, srcAlpha, srcAlpha, 1);
 
     return SkPM4f::From4f(src);
 }