Revert of Move sRGB <-> linear conversion components to their own files.

tests/SRGBTest.cpp

-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkSRGB.h"
-#include "Test.h"
-#include <math.h>
-
-static uint8_t linear_to_srgb(float l) {
-    return (uint8_t)roundf(sk_linear_to_srgb(Sk4f{l})[0]);
-}
-
-DEF_TEST(sk_linear_to_srgb, r) {
-    // Should map 0 -> 0 and 1 -> 1.
-    REPORTER_ASSERT(r,   0 == linear_to_srgb(0.0f));
-    REPORTER_ASSERT(r, 255 == linear_to_srgb(1.0f));
-
-    // Should be monotonic between 0 and 1.
-    // We don't bother checking denorm values.
-    uint8_t prev = 0;
-    for (float f = FLT_MIN; f <= 1.0f; ) {
-        uint8_t srgb = linear_to_srgb(f);
-
-        REPORTER_ASSERT(r, srgb >= prev);
-        prev = srgb;
-
-        union { float flt; uint32_t bits; } pun = { f };
-        pun.bits++;
-        f = pun.flt;
-    }
-}