Set SkColorSpace object for PNGs and parse ICC profiles

tests/ColorSpaceTest.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 "Resources.h"
+#include "SkCodec.h"
+#include "SkColorSpace.h"
+#include "Test.h"
+
+static SkStreamAsset* resource(const char path[]) {
+    SkString fullPath = GetResourcePath(path);
+    return SkStream::NewFromFile(fullPath.c_str());
+}
+
+static bool almost_equal(float a, float b) {
+    return SkTAbs(a - b) < 0.0001f;
+}
+
+DEF_TEST(ColorSpaceParseICCProfile, r) {
+    SkAutoTDelete<SkStream> stream(resource("color_wheel_with_profile.png"));
+    REPORTER_ASSERT(r, nullptr != stream);
+
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.detach()));
+    REPORTER_ASSERT(r, nullptr != codec);
+
+    SkColorSpace* colorSpace = codec->getColorSpace();
+    REPORTER_ASSERT(r, nullptr != colorSpace);
+
+    // No need to use almost equal here.  The color profile that we have extracted
+    // actually has a table of gammas.  And our current implementation guesses 2.2f.
+    SkFloat3 gammas = colorSpace->gamma();
+    REPORTER_ASSERT(r, 2.2f == gammas.fVec[0]);
+    REPORTER_ASSERT(r, 2.2f == gammas.fVec[1]);
+    REPORTER_ASSERT(r, 2.2f == gammas.fVec[2]);
+
+    // These nine values were extracted from the color profile in isolation (before
+    // we embedded it in the png).  Here we check that we still extract the same values.
+    SkFloat3x3 xyz = colorSpace->xyz();
+    REPORTER_ASSERT(r, almost_equal(0.436066f, xyz.fMat[0]));
+    REPORTER_ASSERT(r, almost_equal(0.222488f, xyz.fMat[1]));
+    REPORTER_ASSERT(r, almost_equal(0.013916f, xyz.fMat[2]));
+    REPORTER_ASSERT(r, almost_equal(0.385147f, xyz.fMat[3]));
+    REPORTER_ASSERT(r, almost_equal(0.716873f, xyz.fMat[4]));
+    REPORTER_ASSERT(r, almost_equal(0.0970764f, xyz.fMat[5]));
+    REPORTER_ASSERT(r, almost_equal(0.143066f, xyz.fMat[6]));
+    REPORTER_ASSERT(r, almost_equal(0.0606079f, xyz.fMat[7]));
+    REPORTER_ASSERT(r, almost_equal(0.714096f, xyz.fMat[8]));
+}