Revert of expand unitests for color4f (patchset #1 id:1 of https://codereview.chromium.org/1622893002/ )

Reason for revert:
leaking shadercontext in test

Original issue's description:
> expand unitests for color4f
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1622893002
>
> TBR=
>
> Committed: https://skia.googlesource.com/skia/+/fac684502b6047ffc7dc2e59bd7e5a7cbfa5bf78

TBR=
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1622923002
diff --git a/tests/SkColor4fTest.cpp b/tests/SkColor4fTest.cpp
index 6069246..b09b0c4 100644
--- a/tests/SkColor4fTest.cpp
+++ b/tests/SkColor4fTest.cpp
@@ -6,30 +6,11 @@
  */
 
 #include "SkColor.h"
-#include "SkColorMatrixFilter.h"
-#include "SkGradientShader.h"
-#include "SkImage.h"
 #include "SkShader.h"
-
+#include "SkColorMatrixFilter.h"
 #include "Test.h"
 #include "SkRandom.h"
 
-const float kTolerance = 1.0f / (1 << 20);
-
-static bool nearly_equal(float a, float b, float tol = kTolerance) {
-    SkASSERT(tol >= 0);
-    return fabsf(a - b) <= tol;
-}
-
-static bool nearly_equal(const SkPM4f a, const SkPM4f& b, float tol = kTolerance) {
-    for (int i = 0; i < 4; ++i) {
-        if (!nearly_equal(a.fVec[i], b.fVec[i], tol)) {
-            return false;
-        }
-    }
-    return true;
-}
-
 DEF_TEST(SkColor4f_FromColor, reporter) {
     const struct {
         SkColor     fC;
@@ -50,7 +31,12 @@
     }
 }
 
-DEF_TEST(Color4f_premul, reporter) {
+static bool nearly_equal(float a, float b) {
+    const float kTolerance = 1.0f / (1 << 20);
+    return fabsf(a - b) < kTolerance;
+}
+
+DEF_TEST(SkColor4f_premul, reporter) {
     SkRandom rand;
 
     for (int i = 0; i < 1000000; ++i) {
@@ -74,119 +60,3 @@
         REPORTER_ASSERT(reporter, nearly_equal(pm4.fVec[SK_B_INDEX], c4.fA * c4.fB));
     }
 }
-
-//////////////////////////////////////////////////////////////////////////////////////////////////
-
-static SkShader* make_color() { return SkShader::CreateColorShader(0xFFBB8855); }
-
-static SkShader* make_image() {
-    const SkImageInfo info = SkImageInfo::MakeN32Premul(2, 2);
-    const SkPMColor pixels[] {
-        SkPackARGB32(0xFF, 0xBB, 0x88, 0x55),
-        SkPackARGB32(0xFF, 0xBB, 0x88, 0x55),
-        SkPackARGB32(0xFF, 0xBB, 0x88, 0x55),
-        SkPackARGB32(0xFF, 0xBB, 0x88, 0x55),
-    };
-    SkAutoTUnref<SkImage> image(SkImage::NewRasterCopy(info, pixels, sizeof(SkPMColor) * 2));
-    return image->newShader(SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
-}
-
-static SkShader* make_grad() {
-    const SkPoint pts[] {{ 0, 0 }, { 100, 100 }};
-    const SkColor colors[] { SK_ColorRED, SK_ColorBLUE };
-    return SkGradientShader::CreateLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
-}
-
-static void compare_spans(const SkPM4f span4f[], const SkPMColor span4b[], int count,
-                          skiatest::Reporter* reporter) {
-    for (int i = 0; i < count; ++i) {
-        SkPM4f c0 = SkPM4f::FromPMColor(span4b[i]);
-        SkPM4f c1 = span4f[i];
-        REPORTER_ASSERT(reporter, nearly_equal(c0, c1, 1.0f/255));
-    }
-}
-
-DEF_TEST(Color4f_shader, reporter) {
-    struct {
-        SkShader*   (*fFact)();
-        bool        fSupports4f;
-    } recs[] = {
-        { make_color, true },
-        { make_grad,  false },
-        { make_image, false },
-    };
-
-    SkPaint paint;
-    for (const auto& rec : recs) {
-        uint32_t storage[200];
-        paint.setShader(rec.fFact())->unref();
-        SkASSERT(paint.getShader()->contextSize() <= sizeof(storage));
-        SkShader::Context* ctx = paint.getShader()->createContext({paint, SkMatrix::I(), nullptr},
-                                                                  storage);
-        REPORTER_ASSERT(reporter, ctx->supports4f() == rec.fSupports4f);
-        if (ctx->supports4f()) {
-            const int N = 100;
-            SkPM4f buffer4f[N];
-            ctx->shadeSpan4f(0, 0, buffer4f, N);
-            SkPMColor buffer4b[N];
-            ctx->shadeSpan(0, 0, buffer4b, N);
-            compare_spans(buffer4f, buffer4b, N, reporter);
-        }
-        ctx->SkShader::Context::~Context();
-    }
-}
-
-static SkColorFilter* make_mode_cf() {
-    return SkColorFilter::CreateModeFilter(0xFFBB8855, SkXfermode::kPlus_Mode);
-}
-
-static SkColorFilter* make_mx_cf() {
-    const float mx[] = {
-        0.5f, 0,    0, 0, 0.1f,
-        0,    0.5f, 0, 0, 0.2f,
-        0,    0,    1, 0, -0.1f,
-        0,    0,    0, 1, 0,
-    };
-    return SkColorMatrixFilter::Create(mx);
-}
-
-static SkColorFilter* make_compose_cf() {
-    SkAutoTUnref<SkColorFilter> cf0(make_mode_cf());
-    SkAutoTUnref<SkColorFilter> cf1(make_mx_cf());
-    return SkColorFilter::CreateComposeFilter(cf0, cf1);
-}
-
-DEF_TEST(Color4f_colorfilter, reporter) {
-    struct {
-        SkColorFilter* (*fFact)();
-        bool           fSupports4f;
-    } recs[] = {
-        { make_mode_cf,     false },
-        { make_mx_cf,       true },
-        { make_compose_cf,  false },
-    };
-
-    // prepare the src
-    const int N = 100;
-    SkPMColor src4b[N];
-    SkPM4f    src4f[N];
-    SkRandom rand;
-    for (int i = 0; i < N; ++i) {
-        src4b[i] = SkPreMultiplyColor(rand.nextU());
-        src4f[i] = SkPM4f::FromPMColor(src4b[i]);
-    }
-    // confirm that our srcs are (nearly) equal
-    compare_spans(src4f, src4b, N, reporter);
-
-    for (const auto& rec : recs) {
-        SkAutoTUnref<SkColorFilter> filter(rec.fFact());
-        REPORTER_ASSERT(reporter, filter->supports4f() == rec.fSupports4f);
-        if (filter->supports4f()) {
-            SkPMColor dst4b[N];
-            filter->filterSpan(src4b, N, dst4b);
-            SkPM4f dst4f[N];
-            filter->filterSpan4f(src4f, N, dst4f);
-            compare_spans(dst4f, dst4b, N, reporter);
-        }
-    }
-}