Reland "strip down SkICC.cpp"

This reverts commit 27fe397bc0cc1b091f9f85863c62b88156239cf0.

Reason for revert: time to fly.

Original change's description:
> Revert "strip down SkICC.cpp"
> 
> This reverts commit eab50eb9c6117c2a9d0e5648f89cebbb4dbd9d30
> and this tiny bit of e61b969a07ba3ebe9e47e61381ad16c5d2c549a2:
> 
>     https://skia-review.googlesource.com/c/skia/+/127122/3/tests/ICCTest.cpp
> 
> Change-Id: I4306e5118a4e5eb88c05078186a28bd443fd76f7
> Reviewed-on: https://skia-review.googlesource.com/127305
> Reviewed-by: Mike Klein <mtklein@chromium.org>
> Commit-Queue: Mike Klein <mtklein@chromium.org>

TBR=mtklein@chromium.org,brianosman@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I93a6cfb66f0da0e098fdcb77ac1cd619e41614b1
Reviewed-on: https://skia-review.googlesource.com/129446
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>

5 files changed, 107 insertions, 568 deletions

diff --git a/include/core/SkICC.h b/include/core/SkICC.h
index 8c5ec566b7..9d2ada347e 100644
--- a/include/core/SkICC.h
+++ b/include/core/SkICC.h
@@ -12,98 +12,26 @@
 #include "SkRefCnt.h"
 
 struct SkColorSpaceTransferFn;
-class SkColorSpace;
-class SkData;
-class SkMatrix44;
 
-class SK_API SkICC : public SkRefCnt {
-public:
+SK_API sk_sp<SkData> SkWriteICCProfile(const SkColorSpaceTransferFn&, const float toXYZD50[9]);
 
-    /**
-     *  Parse an ICC profile.
-     *
-     *  Returns nullptr if the data is not a valid ICC profile or if the profile
-     *  input space is not RGB.
-     */
-    static sk_sp<SkICC> Make(const void*, size_t);
+namespace SkICC {
+    static inline sk_sp<SkData> WriteToICC(const SkColorSpaceTransferFn& fn,
+                                           const SkMatrix44& toXYZD50) {
+        if (toXYZD50.get(3,0) == 0 && toXYZD50.get(3,1) == 0 && toXYZD50.get(3,2) == 0 &&
+            toXYZD50.get(3,3) == 1 &&
+            toXYZD50.get(0,3) == 0 && toXYZD50.get(1,3) == 0 && toXYZD50.get(2,3) == 0) {
 
-    /**
-     *  If the gamut can be represented as transformation into XYZ D50, returns
-     *  true and sets the proper values in |toXYZD50|.
-     *
-     *  If not, returns false.  This indicates that the ICC data is too complex
-     *  to isolate a simple gamut transformation.
-     */
-    bool toXYZD50(SkMatrix44* toXYZD50) const;
+            float m33[9];
+            for (int r = 0; r < 3; r++)
+            for (int c = 0; c < 3; c++) {
+                m33[3*r+c] = toXYZD50.get(r,c);
+            }
+            return SkWriteICCProfile(fn, m33);
 
-    /**
-     *  If the transfer function can be represented as coefficients to the standard
-     *  equation, returns true and sets |fn| to the proper values.
-     *
-     *  If not, returns false.  This indicates one of the following:
-     *  (1) The R, G, and B transfer functions are not the same.
-     *  (2) The transfer function is represented as a table that we have not managed
-     *      to match to a standard curve.
-     *  (3) The ICC data is too complex to isolate a single transfer function.
-     */
-    bool isNumericalTransferFn(SkColorSpaceTransferFn* fn) const;
-
-    /**
-     *  Please do not call this unless isNumericalTransferFn() has been called and it
-     *  fails.  SkColorSpaceTransferFn is the preferred representation.
-     *
-     *  If it is not possible to represent the R, G, and B transfer functions numerically
-     *  and it is still necessary to get the transfer function, this will return the
-     *  transfer functions as three tables (R, G, and B).
-     *
-     *  If possible, this will return tables of the same length as they were specified in
-     *  the ICC profile.  This means that the lengths of the three tables are not
-     *  guaranteed to be the same.  If the ICC representation was not a table, the length
-     *  will be chosen arbitrarily.
-     *
-     *  The lengths of the tables are all guaranteed to be at least 2.  Entries in the
-     *  tables are guaranteed to be in [0, 1].
-     *
-     *  This API may be deleted in favor of a numerical approximation of the raw data.
-     *
-     *  This function may fail, indicating that the ICC profile does not have transfer
-     *  functions.
-     */
-    struct Channel {
-        // Byte offset of the start of the table in |fStorage|
-        size_t fOffset;
-        int    fCount;
-    };
-    struct Tables {
-        Channel fRed;
-        Channel fGreen;
-        Channel fBlue;
-
-        const float* red() {
-            return (const float*) (fStorage->bytes() + fRed.fOffset);
-        }
-        const float* green() {
-            return (const float*) (fStorage->bytes() + fGreen.fOffset);
         }
-        const float* blue() {
-            return (const float*) (fStorage->bytes() + fBlue.fOffset);
-        }
-
-        sk_sp<SkData> fStorage;
-    };
-    bool rawTransferFnData(Tables* tables) const;
-
-    /**
-     *  Write an ICC profile with transfer function |fn| and gamut |toXYZD50|.
-     */
-    static sk_sp<SkData> WriteToICC(const SkColorSpaceTransferFn& fn, const SkMatrix44& toXYZD50);
-
-private:
-    SkICC(sk_sp<SkColorSpace> colorSpace);
-
-    sk_sp<SkColorSpace> fColorSpace;
-
-    friend class ICCTest;
-};
+        return nullptr;
+    }
+}
 
-#endif
+#endif//SkICC_DEFINED
diff --git a/src/core/SkICC.cpp b/src/core/SkICC.cpp
index 3a77dfc200..aa9c45e50b 100644
--- a/src/core/SkICC.cpp
+++ b/src/core/SkICC.cpp
@@ -7,134 +7,13 @@
 
 #include "SkAutoMalloc.h"
 #include "SkColorSpacePriv.h"
-#include "SkColorSpaceXformPriv.h"
-#include "SkColorSpace_XYZ.h"
 #include "SkEndian.h"
 #include "SkFixed.h"
 #include "SkICC.h"
 #include "SkICCPriv.h"
 #include "SkMD5.h"
-#include "SkString.h"
 #include "SkUtils.h"
 
-SkICC::SkICC(sk_sp<SkColorSpace> colorSpace)
-    : fColorSpace(std::move(colorSpace))
-{}
-
-sk_sp<SkICC> SkICC::Make(const void* ptr, size_t len) {
-    sk_sp<SkColorSpace> colorSpace = SkColorSpace::MakeICC(ptr, len);
-    if (!colorSpace) {
-        return nullptr;
-    }
-
-    return sk_sp<SkICC>(new SkICC(std::move(colorSpace)));
-}
-
-bool SkICC::toXYZD50(SkMatrix44* toXYZD50) const {
-    return fColorSpace->toXYZD50(toXYZD50);
-}
-
-bool SkICC::isNumericalTransferFn(SkColorSpaceTransferFn* coeffs) const {
-    return fColorSpace->isNumericalTransferFn(coeffs);
-}
-
-static const int kDefaultTableSize = 512; // Arbitrary
-
-void fn_to_table(float* tablePtr, const SkColorSpaceTransferFn& fn) {
-    // Y = (aX + b)^g + e  for X >= d
-    // Y = cX + f          otherwise
-    for (int i = 0; i < kDefaultTableSize; i++) {
-        float x = ((float) i) / ((float) (kDefaultTableSize - 1));
-        if (x >= fn.fD) {
-            tablePtr[i] = clamp_0_1(powf(fn.fA * x + fn.fB, fn.fG) + fn.fE);
-        } else {
-            tablePtr[i] = clamp_0_1(fn.fC * x + fn.fF);
-        }
-    }
-}
-
-void copy_to_table(float* tablePtr, const SkGammas* gammas, int index) {
-    SkASSERT(gammas->isTable(index));
-    const float* ptr = gammas->table(index);
-    const size_t bytes = gammas->tableSize(index) * sizeof(float);
-    memcpy(tablePtr, ptr, bytes);
-}
-
-bool SkICC::rawTransferFnData(Tables* tables) const {
-    if (!fColorSpace->toXYZD50()) {
-        return false;  // Can't even dream of handling A2B here...
-    }
-    SkColorSpace_XYZ* colorSpace = (SkColorSpace_XYZ*) fColorSpace.get();
-
-    SkColorSpaceTransferFn fn;
-    if (this->isNumericalTransferFn(&fn)) {
-        tables->fStorage = SkData::MakeUninitialized(kDefaultTableSize * sizeof(float));
-        fn_to_table((float*) tables->fStorage->writable_data(), fn);
-        tables->fRed.fOffset = tables->fGreen.fOffset = tables->fBlue.fOffset = 0;
-        tables->fRed.fCount = tables->fGreen.fCount = tables->fBlue.fCount = kDefaultTableSize;
-        return true;
-    }
-
-    const SkGammas* gammas = colorSpace->gammas();
-    SkASSERT(gammas);
-    if (gammas->allChannelsSame()) {
-        SkASSERT(gammas->isTable(0));
-        tables->fStorage = SkData::MakeUninitialized(gammas->tableSize(0) * sizeof(float));
-        copy_to_table((float*) tables->fStorage->writable_data(), gammas, 0);
-        tables->fRed.fOffset = tables->fGreen.fOffset = tables->fBlue.fOffset = 0;
-        tables->fRed.fCount = tables->fGreen.fCount = tables->fBlue.fCount = gammas->tableSize(0);
-        return true;
-    }
-
-    // Determine the storage size.
-    size_t storageSize = 0;
-    for (int i = 0; i < 3; i++) {
-        if (gammas->isTable(i)) {
-            storageSize += gammas->tableSize(i) * sizeof(float);
-        } else {
-            storageSize += kDefaultTableSize * sizeof(float);
-        }
-    }
-
-    // Fill in the tables.
-    tables->fStorage = SkData::MakeUninitialized(storageSize);
-    float* ptr = (float*) tables->fStorage->writable_data();
-    size_t offset = 0;
-    Channel rgb[3];
-    for (int i = 0; i < 3; i++) {
-        if (gammas->isTable(i)) {
-            copy_to_table(ptr, gammas, i);
-            rgb[i].fOffset = offset;
-            rgb[i].fCount = gammas->tableSize(i);
-            offset += rgb[i].fCount * sizeof(float);
-            ptr += rgb[i].fCount;
-            continue;
-        }
-
-        if (gammas->isNamed(i)) {
-            SkAssertResult(named_to_parametric(&fn, gammas->data(i).fNamed));
-        } else if (gammas->isValue(i)) {
-            value_to_parametric(&fn, gammas->data(i).fValue);
-        } else {
-            SkASSERT(gammas->isParametric(i));
-            fn = gammas->params(i);
-        }
-
-        fn_to_table(ptr, fn);
-        rgb[i].fOffset = offset;
-        rgb[i].fCount = kDefaultTableSize;
-        offset += kDefaultTableSize * sizeof(float);
-        ptr += kDefaultTableSize;
-    }
-
-    tables->fRed = rgb[0];
-    tables->fGreen = rgb[1];
-    tables->fBlue = rgb[2];
-    return true;
-}
-
-///////////////////////////////////////////////////////////////////////////////////////////////////
-
 static constexpr char kDescriptionTagBodyPrefix[12] =
         { 'G', 'o', 'o', 'g', 'l', 'e', '/', 'S', 'k', 'i', 'a' , '/'};
 
@@ -165,9 +44,14 @@ static constexpr uint32_t kWhitePointTag[5] {
 
 // Google Inc. 2016 (UTF-16)
 static constexpr uint8_t kCopyrightTagBody[] = {
-        0x00, 0x47, 0x00, 0x6f, 0x00, 0x6f, 0x00, 0x67, 0x00, 0x6c, 0x00, 0x65, 0x00, 0x20, 0x00,
-        0x49, 0x00, 0x6e, 0x00, 0x63, 0x00, 0x2e, 0x00, 0x20, 0x00, 0x32, 0x00, 0x30, 0x00, 0x31,
-        0x00, 0x36,
+        0x00, 0x47, 0x00, 0x6f,
+        0x00, 0x6f, 0x00, 0x67,
+        0x00, 0x6c, 0x00, 0x65,
+        0x00, 0x20, 0x00, 0x49,
+        0x00, 0x6e, 0x00, 0x63,
+        0x00, 0x2e, 0x00, 0x20,
+        0x00, 0x32, 0x00, 0x30,
+        0x00, 0x31, 0x00, 0x36,
 };
 static_assert(SkIsAlign4(sizeof(kCopyrightTagBody)), "Copyright must be aligned to 4-bytes.");
 static constexpr uint32_t kCopyrightTagHeader[7] {
@@ -288,12 +172,12 @@ static SkFixed float_round_to_fixed(float x) {
     return sk_float_saturate2int((float)floor((double)x * SK_Fixed1 + 0.5));
 }
 
-static void write_xyz_tag(uint32_t* ptr, const SkMatrix44& toXYZ, int col) {
+static void write_xyz_tag(uint32_t* ptr, const float toXYZD50[9], int col) {
     ptr[0] = SkEndian_SwapBE32(kXYZ_PCSSpace);
     ptr[1] = 0;
-    ptr[2] = SkEndian_SwapBE32(float_round_to_fixed(toXYZ.getFloat(0, col)));
-    ptr[3] = SkEndian_SwapBE32(float_round_to_fixed(toXYZ.getFloat(1, col)));
-    ptr[4] = SkEndian_SwapBE32(float_round_to_fixed(toXYZ.getFloat(2, col)));
+    ptr[2] = SkEndian_SwapBE32(float_round_to_fixed(toXYZD50[0*3 + col]));
+    ptr[3] = SkEndian_SwapBE32(float_round_to_fixed(toXYZD50[1*3 + col]));
+    ptr[4] = SkEndian_SwapBE32(float_round_to_fixed(toXYZD50[2*3 + col]));
 }
 
 static void write_trc_tag(uint32_t* ptr, const SkColorSpaceTransferFn& fn) {
@@ -309,12 +193,6 @@ static void write_trc_tag(uint32_t* ptr, const SkColorSpaceTransferFn& fn) {
     ptr[9] = SkEndian_SwapBE32(float_round_to_fixed(fn.fF));
 }
 
-static bool is_3x3(const SkMatrix44& toXYZD50) {
-    return 0.0f == toXYZD50.get(3, 0) && 0.0f == toXYZD50.get(3, 1) && 0.0f == toXYZD50.get(3, 2) &&
-           0.0f == toXYZD50.get(0, 3) && 0.0f == toXYZD50.get(1, 3) && 0.0f == toXYZD50.get(2, 3) &&
-           1.0f == toXYZD50.get(3, 3);
-}
-
 static bool nearly_equal(float x, float y) {
     // A note on why I chose this tolerance:  transfer_fn_almost_equal() uses a
     // tolerance of 0.001f, which doesn't seem to be enough to distinguish
@@ -338,28 +216,18 @@ static bool nearly_equal(const SkColorSpaceTransferFn& u,
         && nearly_equal(u.fF, v.fF);
 }
 
-static bool nearly_equal(const SkMatrix44& toXYZD50, const float standard[9]) {
-    return nearly_equal(toXYZD50.getFloat(0, 0), standard[0])
-        && nearly_equal(toXYZD50.getFloat(0, 1), standard[1])
-        && nearly_equal(toXYZD50.getFloat(0, 2), standard[2])
-        && nearly_equal(toXYZD50.getFloat(1, 0), standard[3])
-        && nearly_equal(toXYZD50.getFloat(1, 1), standard[4])
-        && nearly_equal(toXYZD50.getFloat(1, 2), standard[5])
-        && nearly_equal(toXYZD50.getFloat(2, 0), standard[6])
-        && nearly_equal(toXYZD50.getFloat(2, 1), standard[7])
-        && nearly_equal(toXYZD50.getFloat(2, 2), standard[8])
-        && nearly_equal(toXYZD50.getFloat(0, 3), 0.0f)
-        && nearly_equal(toXYZD50.getFloat(1, 3), 0.0f)
-        && nearly_equal(toXYZD50.getFloat(2, 3), 0.0f)
-        && nearly_equal(toXYZD50.getFloat(3, 0), 0.0f)
-        && nearly_equal(toXYZD50.getFloat(3, 1), 0.0f)
-        && nearly_equal(toXYZD50.getFloat(3, 2), 0.0f)
-        && nearly_equal(toXYZD50.getFloat(3, 3), 1.0f);
+static bool nearly_equal(const float u[9], const float v[9]) {
+    for (int i = 0; i < 9; i++) {
+        if (!nearly_equal(u[i], v[i])) {
+            return false;
+        }
+    }
+    return true;
 }
 
 // Return nullptr if the color profile doen't have a special name.
 const char* get_color_profile_description(const SkColorSpaceTransferFn& fn,
-                                          const SkMatrix44& toXYZD50) {
+                                          const float toXYZD50[9]) {
     bool srgb_xfer = nearly_equal(fn, gSRGB_TransferFn);
     bool srgb_gamut = nearly_equal(toXYZD50, gSRGB_toXYZD50);
     if (srgb_xfer && srgb_gamut) {
@@ -400,7 +268,7 @@ const char* get_color_profile_description(const SkColorSpaceTransferFn& fn,
 
 static void get_color_profile_tag(char dst[kICCDescriptionTagSize],
                                  const SkColorSpaceTransferFn& fn,
-                                 const SkMatrix44& toXYZD50) {
+                                 const float toXYZD50[9]) {
     SkASSERT(dst);
     if (const char* description = get_color_profile_description(fn, toXYZD50)) {
         SkASSERT(strlen(description) < kICCDescriptionTagSize);
@@ -410,12 +278,7 @@ static void get_color_profile_tag(char dst[kICCDescriptionTagSize],
     } else {
         strncpy(dst, kDescriptionTagBodyPrefix, sizeof(kDescriptionTagBodyPrefix));
         SkMD5 md5;
-        for (int i = 0; i < 3; ++i) {
-            for (int j = 0; j < 3; ++j) {
-                float value = toXYZD50.getFloat(i,j);
-                md5.write(&value, sizeof(value));
-            }
-        }
+        md5.write(toXYZD50, 9*sizeof(float));
         static_assert(sizeof(fn) == sizeof(float) * 7, "packed");
         md5.write(&fn, sizeof(fn));
         SkMD5::Digest digest;
@@ -430,29 +293,8 @@ static void get_color_profile_tag(char dst[kICCDescriptionTagSize],
     }
 }
 
-SkString SkICCGetColorProfileTag(const SkColorSpaceTransferFn& fn,
-                                 const SkMatrix44& toXYZD50) {
-    char tag[kICCDescriptionTagSize];
-    get_color_profile_tag(tag, fn, toXYZD50);
-    size_t len = kICCDescriptionTagSize;
-    while (len > 0 && tag[len - 1] == '\0') {
-        --len;  // tag is padded out with zeros
-    }
-    SkASSERT(len != 0);
-    return SkString(tag, len);
-}
-
-// returns pointer just beyond where we just wrote.
-static uint8_t* string_copy_ascii_to_utf16be(uint8_t* dst, const char* src, size_t count) {
-    while (count-- > 0) {
-        *dst++ = 0;
-        *dst++ = (uint8_t)(*src++);
-    }
-    return dst;
-}
-
-sk_sp<SkData> SkICC::WriteToICC(const SkColorSpaceTransferFn& fn, const SkMatrix44& toXYZD50) {
-    if (!is_3x3(toXYZD50) || !is_valid_transfer_fn(fn)) {
+sk_sp<SkData> SkWriteICCProfile(const SkColorSpaceTransferFn& fn, const float toXYZD50[9]) {
+    if (!is_valid_transfer_fn(fn)) {
         return nullptr;
     }
 
@@ -473,7 +315,12 @@ sk_sp<SkData> SkICC::WriteToICC(const SkColorSpaceTransferFn& fn, const SkMatrix
     {
         char colorProfileTag[kICCDescriptionTagSize];
         get_color_profile_tag(colorProfileTag, fn, toXYZD50);
-        ptr = string_copy_ascii_to_utf16be(ptr, colorProfileTag, kICCDescriptionTagSize);
+
+        // ASCII --> big-endian UTF-16.
+        for (size_t i = 0; i < kICCDescriptionTagSize; i++) {
+            *ptr++ = 0;
+            *ptr++ = colorProfileTag[i];
+        }
     }
 
     // Write XYZ tags
diff --git a/src/core/SkICCPriv.h b/src/core/SkICCPriv.h
index a50d362a55..3d2b8965a9 100644
--- a/src/core/SkICCPriv.h
+++ b/src/core/SkICCPriv.h
@@ -51,11 +51,4 @@ enum ParaCurveType {
     kGABCDEF_ParaCurveType     = 4,
 };
 
-/*
- * Given fn and toXYZD50, generate a decription tag that either includes a hash
- * of the function and gamut or is a special name.
- * Exposed for unit testing and tools.
- */
-SkString SkICCGetColorProfileTag(const SkColorSpaceTransferFn& fn,
-                                 const SkMatrix44& toXYZD50);
 #endif  // SkICCPriv_DEFINED
diff --git a/src/images/SkImageEncoderFns.h b/src/images/SkImageEncoderFns.h
index 8637541720..d8d1c64bb8 100644
--- a/src/images/SkImageEncoderFns.h
+++ b/src/images/SkImageEncoderFns.h
@@ -427,8 +427,6 @@ static inline sk_sp<SkData> icc_from_color_space(const SkImageInfo& info) {
     if (cs->isNumericalTransferFn(&fn) && cs->toXYZD50(&toXYZD50)) {
         return SkICC::WriteToICC(fn, toXYZD50);
     }
-
-    // TODO: Should we support writing ICC profiles for additional color spaces?
     return nullptr;
 }
 
diff --git a/tests/ICCTest.cpp b/tests/ICCTest.cpp
index 34ed52984c..e88255b2cd 100644
--- a/tests/ICCTest.cpp
+++ b/tests/ICCTest.cpp
@@ -5,296 +5,69 @@
  * found in the LICENSE file.
  */
 
-#include "Resources.h"
-#include "SkColorSpace.h"
-#include "SkColorSpacePriv.h"
-#include "SkColorSpace_XYZ.h"
-#include "SkData.h"
-#include "SkICC.h"
-#include "SkICCPriv.h"
-#include "SkMatrix44.h"
-#include "SkStream.h"
-#include "Test.h"
-
-static bool almost_equal(float a, float b) {
-    return SkTAbs(a - b) < 0.001f;
-}
-
-static inline void test_to_xyz_d50(skiatest::Reporter* r, SkICC* icc, bool shouldSucceed,
-                                   const float* reference) {
-    SkMatrix44 result(SkMatrix44::kUninitialized_Constructor);
-    REPORTER_ASSERT(r, shouldSucceed == icc->toXYZD50(&result));
-    if (shouldSucceed) {
-        float resultVals[16];
-        result.asColMajorf(resultVals);
-        for (int i = 0; i < 16; i++) {
-            REPORTER_ASSERT(r, almost_equal(resultVals[i], reference[i]));
+#include "SkTypes.h"
+
+#if defined(SK_USE_SKCMS)
+
+    #include "Resources.h"
+    #include "SkColorSpacePriv.h"
+    #include "SkICC.h"
+    #include "SkString.h"
+    #include "Test.h"
+    #include "skcms.h"
+
+    DEF_TEST(WriteICCProfile, r) {
+        auto adobeRGB = SkColorSpace::MakeRGB(g2Dot2_TransferFn, SkColorSpace::kAdobeRGB_Gamut);
+
+        struct {
+            SkColorSpaceTransferFn fn;
+            const float*           toXYZD50;
+            const char*            desc;
+            sk_sp<SkColorSpace>    want;
+        } tests[] = {
+            {g2Dot2_TransferFn, gAdobeRGB_toXYZD50, "AdobeRGB", adobeRGB},
+            { gSRGB_TransferFn,     gSRGB_toXYZD50,     "sRGB", SkColorSpace::MakeSRGB()},
+        };
+
+        for (auto test : tests) {
+            sk_sp<SkData> profile = SkWriteICCProfile(test.fn, test.toXYZD50);
+            REPORTER_ASSERT(r, profile);
+
+            skcms_ICCProfile parsed;
+            REPORTER_ASSERT(r, skcms_Parse(profile->data(), profile->size(), &parsed));
+
+            sk_sp<SkColorSpace> got = SkColorSpace::Make(parsed);
+            REPORTER_ASSERT(r, got);
+            REPORTER_ASSERT(r, SkColorSpace::Equals(got.get(), test.want.get()));
+
+            skcms_ICCTag desc;
+            REPORTER_ASSERT(r, skcms_GetTagBySignature(&parsed,
+                                                       SkSetFourByteTag('d','e','s','c'),
+                                                       &desc));
+
+            // Rather than really carefully break down the 'desc' tag,
+            // just check our expected description is somewhere in there (as big-endian UTF-16).
+            uint8_t big_endian_utf16[16];
+            for (size_t i = 0; i < strlen(test.desc); i++) {
+                big_endian_utf16[2*i+0] = 0;
+                big_endian_utf16[2*i+1] = test.desc[i];
+            }
+
+            SkString haystack((const char*)desc.buf, desc.size),
+                     needle  ((const char*)big_endian_utf16, 2*strlen(test.desc));
+            REPORTER_ASSERT(r, haystack.contains(needle.c_str()));
         }
     }
-}
-
-DEF_TEST(ICC_ToXYZD50, r) {
-    const float z30Reference[16] = {
-        0.59825f, 0.27103f, 0.00603f, 0.0f, 0.22243f, 0.67447f, 0.07368f, 0.0f, 0.14352f, 0.05449f,
-        0.74519f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f,
-    };
-
-    sk_sp<SkData> data = GetResourceAsData("icc_profiles/HP_ZR30w.icc");
-    sk_sp<SkICC> z30 = SkICC::Make(data->data(), data->size());
-    test_to_xyz_d50(r, z30.get(), true, z30Reference);
-
-    const float z32Reference[16] = {
-        0.61583f, 0.28789f, 0.00513f, 0.0f, 0.20428f, 0.66972f, 0.06609f, 0.0f, 0.14409f, 0.04237f,
-        0.75368f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f,
-    };
-
-    data = GetResourceAsData("icc_profiles/HP_Z32x.icc");
-    sk_sp<SkICC> z32 = SkICC::Make(data->data(), data->size());
-    test_to_xyz_d50(r, z32.get(), true, z32Reference);
-
-    data = GetResourceAsData("icc_profiles/upperLeft.icc");
-    sk_sp<SkICC> upperLeft = SkICC::Make(data->data(), data->size());
-    test_to_xyz_d50(r, upperLeft.get(), false, z32Reference);
-
-    data = GetResourceAsData("icc_profiles/upperRight.icc");
-    sk_sp<SkICC> upperRight = SkICC::Make(data->data(), data->size());
-    test_to_xyz_d50(r, upperRight.get(), false, z32Reference);
-}
-
-static inline void test_is_numerical_transfer_fn(skiatest::Reporter* r, SkICC* icc,
-                                                 bool shouldSucceed,
-                                                 const SkColorSpaceTransferFn& reference) {
-    SkColorSpaceTransferFn result;
-    REPORTER_ASSERT(r, shouldSucceed == icc->isNumericalTransferFn(&result));
-    if (shouldSucceed) {
-        REPORTER_ASSERT(r, 0 == memcmp(&result, &reference, sizeof(SkColorSpaceTransferFn)));
-    }
-}
-
-DEF_TEST(ICC_IsNumericalTransferFn, r) {
-    SkColorSpaceTransferFn referenceFn;
-    referenceFn.fA = 1.0f;
-    referenceFn.fB = 0.0f;
-    referenceFn.fC = 0.0f;
-    referenceFn.fD = 0.0f;
-    referenceFn.fE = 0.0f;
-    referenceFn.fF = 0.0f;
-    referenceFn.fG = 2.2f;
-
-    sk_sp<SkData> data = GetResourceAsData("icc_profiles/HP_ZR30w.icc");
-    sk_sp<SkICC> z30 = SkICC::Make(data->data(), data->size());
-    test_is_numerical_transfer_fn(r, z30.get(), true, referenceFn);
-
-    data = GetResourceAsData("icc_profiles/HP_Z32x.icc");
-    sk_sp<SkICC> z32 = SkICC::Make(data->data(), data->size());
-    test_is_numerical_transfer_fn(r, z32.get(), true, referenceFn);
-
-    data = GetResourceAsData("icc_profiles/upperLeft.icc");
-    sk_sp<SkICC> upperLeft = SkICC::Make(data->data(), data->size());
-    test_is_numerical_transfer_fn(r, upperLeft.get(), false, referenceFn);
-
-    data = GetResourceAsData("icc_profiles/upperRight.icc");
-    sk_sp<SkICC> upperRight = SkICC::Make(data->data(), data->size());
-    test_is_numerical_transfer_fn(r, upperRight.get(), false, referenceFn);
-}
-
-DEF_TEST(ICC_Adobe, r) {
-    // Test that the color spaces produced by our procedural Adobe factory, and the official
-    // Adobe ICC profile match exactly.
-    sk_sp<SkData> data = GetResourceAsData("icc_profiles/AdobeRGB1998.icc");
-    sk_sp<SkColorSpace> fromIcc = SkColorSpace::MakeICC(data->data(), data->size());
-    sk_sp<SkColorSpace> procedural = SkColorSpace::MakeRGB(g2Dot2_TransferFn,
-                                                           SkColorSpace::kAdobeRGB_Gamut);
-    REPORTER_ASSERT(r, SkColorSpace::Equals(fromIcc.get(), procedural.get()));
-}
-
-static inline void test_write_icc(skiatest::Reporter* r, const SkColorSpaceTransferFn& fn,
-                                  const SkMatrix44& toXYZD50, bool writeToFile) {
-    sk_sp<SkData> profile = SkICC::WriteToICC(fn, toXYZD50);
-    if (writeToFile) {
-        SkFILEWStream stream("out.icc");
-        stream.write(profile->data(), profile->size());
-    }
-
-    sk_sp<SkColorSpace> colorSpace = SkColorSpace::MakeICC(profile->data(), profile->size());
-    sk_sp<SkColorSpace> reference = SkColorSpace::MakeRGB(fn, toXYZD50);
-    REPORTER_ASSERT(r, SkColorSpace::Equals(reference.get(), colorSpace.get()));
-}
-
-DEF_TEST(ICC_WriteICC, r) {
-    SkColorSpaceTransferFn adobeFn;
-    adobeFn.fA = 1.0f;
-    adobeFn.fB = 0.0f;
-    adobeFn.fC = 0.0f;
-    adobeFn.fD = 0.0f;
-    adobeFn.fE = 0.0f;
-    adobeFn.fF = 0.0f;
-    adobeFn.fG = 2.2f;
-    SkMatrix44 adobeMatrix(SkMatrix44::kUninitialized_Constructor);
-    adobeMatrix.set3x3RowMajorf(gAdobeRGB_toXYZD50);
-    test_write_icc(r, adobeFn, adobeMatrix, false);
-
-    SkColorSpaceTransferFn srgbFn;
-    srgbFn.fA = 1.0f / 1.055f;
-    srgbFn.fB = 0.055f / 1.055f;
-    srgbFn.fC = 1.0f / 12.92f;
-    srgbFn.fD = 0.04045f;
-    srgbFn.fE = 0.0f;
-    srgbFn.fF = 0.0f;
-    srgbFn.fG = 2.4f;
-    SkMatrix44 srgbMatrix(SkMatrix44::kUninitialized_Constructor);
-    srgbMatrix.set3x3RowMajorf(gSRGB_toXYZD50);
-    test_write_icc(r, srgbFn, srgbMatrix, false);
-
-    SkString adobeTag = SkICCGetColorProfileTag(adobeFn, adobeMatrix);
-    SkString srgbTag = SkICCGetColorProfileTag(srgbFn, srgbMatrix);
-    REPORTER_ASSERT(r, adobeTag != srgbTag);
-    REPORTER_ASSERT(r, srgbTag.equals("sRGB"));
-    REPORTER_ASSERT(r, adobeTag.equals("AdobeRGB"));
-}
-
-static inline void test_raw_transfer_fn(skiatest::Reporter* r, SkICC* icc) {
-    SkICC::Tables tables;
-    bool result = icc->rawTransferFnData(&tables);
-    REPORTER_ASSERT(r, result);
 
-    REPORTER_ASSERT(r, 0.0f == tables.red()[0]);
-    REPORTER_ASSERT(r, 0.0f == tables.green()[0]);
-    REPORTER_ASSERT(r, 0.0f == tables.blue()[0]);
-    REPORTER_ASSERT(r, 1.0f == tables.red()[tables.fRed.fCount - 1]);
-    REPORTER_ASSERT(r, 1.0f == tables.green()[tables.fGreen.fCount - 1]);
-    REPORTER_ASSERT(r, 1.0f == tables.blue()[tables.fBlue.fCount - 1]);
-}
+    DEF_TEST(AdobeRGB, r) {
+        if (sk_sp<SkData> profile = GetResourceAsData("icc_profiles/AdobeRGB1998.icc")) {
+            skcms_ICCProfile parsed;
+            REPORTER_ASSERT(r, skcms_Parse(profile->data(), profile->size(), &parsed));
 
-class ICCTest {
-public:
-    static sk_sp<SkICC> MakeICC(sk_sp<SkColorSpace> space) {
-        return sk_sp<SkICC>(new SkICC(std::move(space)));
-    }
-    static sk_sp<SkICC> MakeICC(sk_sp<SkGammas> gammas) {
-        return MakeICC(sk_sp<SkColorSpace>(new SkColorSpace_XYZ(
-                kNonStandard_SkGammaNamed, std::move(gammas),
-                SkMatrix44(SkMatrix44::kIdentity_Constructor), nullptr)));
-    }
-};
-
-DEF_TEST(ICC_RawTransferFns, r) {
-    sk_sp<SkICC> srgb = ICCTest::MakeICC(SkColorSpace::MakeSRGB());
-    test_raw_transfer_fn(r, srgb.get());
-
-    // Lookup-table based gamma curves
-    constexpr size_t tableSize = 10;
-    void* memory = sk_malloc_throw(sizeof(SkGammas) + sizeof(float) * tableSize);
-    sk_sp<SkGammas> gammas = sk_sp<SkGammas>(new (memory) SkGammas(3));
-    for (int i = 0; i < 3; ++i) {
-        gammas->fType[i] = SkGammas::Type::kTable_Type;
-        gammas->fData[i].fTable.fSize = tableSize;
-        gammas->fData[i].fTable.fOffset = 0;
-    }
-
-    float* table = SkTAddOffset<float>(memory, sizeof(SkGammas));
-    table[0] = 0.00f;
-    table[1] = 0.05f;
-    table[2] = 0.10f;
-    table[3] = 0.15f;
-    table[4] = 0.25f;
-    table[5] = 0.35f;
-    table[6] = 0.45f;
-    table[7] = 0.60f;
-    table[8] = 0.75f;
-    table[9] = 1.00f;
-    sk_sp<SkICC> tbl = ICCTest::MakeICC(gammas);
-    test_raw_transfer_fn(r, tbl.get());
-
-    // Parametric gamma curves
-    memory = sk_malloc_throw(sizeof(SkGammas) + sizeof(SkColorSpaceTransferFn));
-    gammas = sk_sp<SkGammas>(new (memory) SkGammas(3));
-    for (int i = 0; i < 3; ++i) {
-        gammas->fType[i] = SkGammas::Type::kParam_Type;
-        gammas->fData[i].fParamOffset = 0;
-    }
-
-    SkColorSpaceTransferFn* params = SkTAddOffset<SkColorSpaceTransferFn>
-            (memory, sizeof(SkGammas));
-
-    // Interval.
-    params->fD = 0.04045f;
-
-    // First equation:
-    params->fC = 1.0f / 12.92f;
-    params->fF = 0.0f;
-
-    // Second equation:
-    // Note that the function is continuous (it's actually sRGB).
-    params->fA = 1.0f / 1.055f;
-    params->fB = 0.055f / 1.055f;
-    params->fE = 0.0f;
-    params->fG = 2.4f;
-    sk_sp<SkICC> param = ICCTest::MakeICC(gammas);
-    test_raw_transfer_fn(r, param.get());
-
-    // Exponential gamma curves
-    gammas = sk_sp<SkGammas>(new SkGammas(3));
-    for (int i = 0; i < 3; ++i) {
-        gammas->fType[i] = SkGammas::Type::kValue_Type;
-        gammas->fData[i].fValue = 1.4f;
+            auto got  = SkColorSpace::Make(parsed);
+            auto want = SkColorSpace::MakeRGB(g2Dot2_TransferFn, SkColorSpace::kAdobeRGB_Gamut);
+            REPORTER_ASSERT(r, SkColorSpace::Equals(got.get(), want.get()));
+        }
     }
-    sk_sp<SkICC> exp = ICCTest::MakeICC(gammas);
-    test_raw_transfer_fn(r, exp.get());
-
-    gammas = sk_sp<SkGammas>(new SkGammas(3));
-    gammas->fType[0] = gammas->fType[1] = gammas->fType[2] = SkGammas::Type::kNamed_Type;
-    gammas->fData[0].fNamed = kSRGB_SkGammaNamed;
-    gammas->fData[1].fNamed = k2Dot2Curve_SkGammaNamed;
-    gammas->fData[2].fNamed = kLinear_SkGammaNamed;
-    sk_sp<SkICC> named = ICCTest::MakeICC(gammas);
-    test_raw_transfer_fn(r, named.get());
-
-    memory = sk_malloc_throw(sizeof(SkGammas) + sizeof(float) * tableSize +
-                                   sizeof(SkColorSpaceTransferFn));
-    gammas = sk_sp<SkGammas>(new (memory) SkGammas(3));
-
-    table = SkTAddOffset<float>(memory, sizeof(SkGammas));
-    table[0] = 0.00f;
-    table[1] = 0.15f;
-    table[2] = 0.20f;
-    table[3] = 0.25f;
-    table[4] = 0.35f;
-    table[5] = 0.45f;
-    table[6] = 0.55f;
-    table[7] = 0.70f;
-    table[8] = 0.85f;
-    table[9] = 1.00f;
-
-    params = SkTAddOffset<SkColorSpaceTransferFn>(memory,
-            sizeof(SkGammas) + sizeof(float) * tableSize);
-    params->fA = 1.0f / 1.055f;
-    params->fB = 0.055f / 1.055f;
-    params->fC = 1.0f / 12.92f;
-    params->fD = 0.04045f;
-    params->fE = 0.0f;
-    params->fF = 0.0f;
-    params->fG = 2.4f;
-
-    gammas->fType[0] = SkGammas::Type::kValue_Type;
-    gammas->fData[0].fValue = 1.2f;
-
-    gammas->fType[1] = SkGammas::Type::kTable_Type;
-    gammas->fData[1].fTable.fSize = tableSize;
-    gammas->fData[1].fTable.fOffset = 0;
-
-    gammas->fType[2] = SkGammas::Type::kParam_Type;
-    gammas->fData[2].fParamOffset = sizeof(float) * tableSize;
-    sk_sp<SkICC> nonstd = ICCTest::MakeICC(gammas);
-    test_raw_transfer_fn(r, nonstd.get());
-
-    // Reverse order of table and exponent
-    gammas->fType[1] = SkGammas::Type::kValue_Type;
-    gammas->fData[1].fValue = 1.2f;
 
-    gammas->fType[0] = SkGammas::Type::kTable_Type;
-    gammas->fData[0].fTable.fSize = tableSize;
-    gammas->fData[0].fTable.fOffset = 0;
-    sk_sp<SkICC> nonstd2 = ICCTest::MakeICC(gammas);
-    test_raw_transfer_fn(r, nonstd2.get());
-}
+#endif