Add support for PNG representation in gfx::Image

ui/gfx/image/image_unittest.cc

Index: ui/gfx/image/image_unittest.cc
diff --git a/ui/gfx/image/image_unittest.cc b/ui/gfx/image/image_unittest.cc
index 0cdc237fabb3c356077697b766f71facb7b98cb4..d4811bd9e924fe431bd69aed464f7ad390e29025 100644
--- a/ui/gfx/image/image_unittest.cc
+++ b/ui/gfx/image/image_unittest.cc
@@ -93,6 +93,33 @@ TEST_F(ImageTest, SkiaToSkiaRef) {
     EXPECT_FALSE(image.HasRepresentation(gt::GetPlatformRepresentationType()));
 }
 
+TEST_F(ImageTest, SkiaToPNGEncodeAndDecode) {
+  gfx::Image image(gt::CreateBitmap(25, 25));
+  const std::vector<unsigned char>* png = image.ToImagePNG();
+  EXPECT_TRUE(png);
+  EXPECT_FALSE(png->empty());
+  EXPECT_TRUE(image.HasRepresentation(gfx::Image::kImageRepPNG));
+
+  gfx::Image from_png(*png);
+  EXPECT_TRUE(image.HasRepresentation(gfx::Image::kImageRepPNG));
+  EXPECT_TRUE(image.HasRepresentation(gfx::Image::kImageRepSkia));
+  EXPECT_TRUE(gt::IsEqual(from_png, image));
+}
+
+TEST_F(ImageTest, PlatformToPNGEncodeAndDecode) {
+  gfx::Image image(gt::CreatePlatformImage());
+  const std::vector<unsigned char>* png = image.ToImagePNG();
+  EXPECT_TRUE(png);
+  EXPECT_FALSE(png->empty());
+  EXPECT_TRUE(image.HasRepresentation(gfx::Image::kImageRepPNG));
+
+  gfx::Image from_png(*png);
+  EXPECT_TRUE(image.HasRepresentation(gfx::Image::kImageRepPNG));
+  EXPECT_TRUE(image.HasRepresentation(gt::GetPlatformRepresentationType()));
+  EXPECT_TRUE(gt::IsPlatformImageValid(gt::ToPlatformType(image)));
+}
+
+
 TEST_F(ImageTest, SkiaToPlatform) {
   gfx::Image image(gt::CreateBitmap(25, 25));
   const size_t kRepCount = kUsesSkiaNatively ? 1U : 2U;