Add test for ICC profile

tests/ImageSharp.Tests/Formats/Png/PngEncoderTests.Chunks.cs

@@ -302,6 +302,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png
             {
                 PngChunkType.Header,
                 PngChunkType.Gamma,
+                PngChunkType.EmbeddedColorProfile,
                 PngChunkType.Palette,
                 PngChunkType.InternationalText,
                 PngChunkType.Text,

tests/ImageSharp.Tests/Formats/Png/PngMetadataTests.cs

@@ -17,7 +17,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png
     public class PngMetadataTests
     {
         public static readonly TheoryData<string, int, int, PixelResolutionUnit> RatioFiles =
-            new TheoryData<string, int, int, PixelResolutionUnit>
+            new()
             {
                 { TestImages.Png.Splash, 11810, 11810, PixelResolutionUnit.PixelsPerMeter },
                 { TestImages.Png.Ratio1x4, 1, 4, PixelResolutionUnit.AspectRatio },
@@ -222,6 +222,33 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png
             }
         }
 
+        [Theory]
+        [WithFile(TestImages.Png.PngWithMetadata, PixelTypes.Rgba32)]
+        public void Encode_PreservesColorProfile<TPixel>(TestImageProvider<TPixel> provider)
+            where TPixel : unmanaged, IPixel<TPixel>
+        {
+            using (Image<TPixel> input = provider.GetImage(new PngDecoder()))
+            {
+                ImageSharp.Metadata.Profiles.Icc.IccProfile expectedProfile = input.Metadata.IccProfile;
+                byte[] expectedProfileBytes = expectedProfile.ToByteArray();
+
+                using (var memStream = new MemoryStream())
+                {
+                    input.Save(memStream, new PngEncoder());
+
+                    memStream.Position = 0;
+                    using (var output = Image.Load<Rgba32>(memStream))
+                    {
+                        ImageSharp.Metadata.Profiles.Icc.IccProfile actualProfile = output.Metadata.IccProfile;
+                        byte[] actualProfileBytes = actualProfile.ToByteArray();
+
+                        Assert.NotNull(actualProfile);
+                        Assert.Equal(expectedProfileBytes, actualProfileBytes);
+                    }
+                }
+            }
+        }
+
         [Theory]
         [MemberData(nameof(RatioFiles))]
         public void Identify_VerifyRatio(string imagePath, int xResolution, int yResolution, PixelResolutionUnit resolutionUnit)