Added kSRGBLinear_Named color space, along with tests

gm/colorspacexform.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkColor.h"
 #include "SkColorSpaceXform.h"
@@ skipping 42 matching lines @@
     SkISize onISize() override {
         return SkISize::Make(500, 200);
     }
 
     void onDraw(SkCanvas* canvas) override {
         auto drawColors = [canvas](SkColor4f* colors) {
             SkRect r = SkRect::MakeXYWH(0.0f, 0.0f, 50.0f, 100.0f);
 
             canvas->save();
             for (int i = 0; i < kNumColors; i++) {
-                sk_sp<SkColorSpace> space =
-                        SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named)->makeLinearGamma();
+                sk_sp<SkColorSpace> space = SkColorSpace::NewNamed(SkColorSpace::kSRGBLinear_Named);
                 sk_sp<SkShader> s = SkShader::MakeColorShader(colors[i], space);
                 SkPaint paint;
                 paint.setShader(s);
                 canvas->drawRect(r, paint);
                 canvas->translate(50.0f, 0.0f);
             }
             canvas->restore();
         };
 
         // Wide gamut colors should appear darker - we are simulating a more intense display.
         drawColors(fSRGBColors);
         canvas->translate(0.0f, 100.0f);
         drawColors(fWideGamutColors);
     }
 
 private:
     static constexpr int kNumColors = 10;
 
     SkColor4f fSRGBColors[kNumColors];
     SkColor4f fWideGamutColors[kNumColors];
 
     typedef skiagm::GM INHERITED;
 };
 
 DEF_GM(return new ColorSpaceXformGM;)