Add support for transparent/translucent pixels in the user image

chrome/browser/chromeos/login/users/avatar/user_image_manager_test_util.cc

Index: chrome/browser/chromeos/login/users/avatar/user_image_manager_test_util.cc
diff --git a/chrome/browser/chromeos/login/users/avatar/user_image_manager_test_util.cc b/chrome/browser/chromeos/login/users/avatar/user_image_manager_test_util.cc
index a26a6cb1f0219292b88fb913c042b1adec577475..33e8b476bbdc7bd027848b4fe2ed69be58efba62 100644
--- a/chrome/browser/chromeos/login/users/avatar/user_image_manager_test_util.cc
+++ b/chrome/browser/chromeos/login/users/avatar/user_image_manager_test_util.cc
@@ -21,6 +21,7 @@ namespace test {
 
 const char kUserAvatarImage1RelativePath[] = "chromeos/avatar1.jpg";
 const char kUserAvatarImage2RelativePath[] = "chromeos/avatar2.jpg";
+const char kUserAvatarImage3RelativePath[] = "chromeos/avatar3.png";
 
 bool AreImagesEqual(const gfx::ImageSkia& first, const gfx::ImageSkia& second) {
   if (first.width() != second.width() || first.height() != second.height())
@@ -56,8 +57,11 @@ ImageLoader::~ImageLoader() {
 std::unique_ptr<gfx::ImageSkia> ImageLoader::Load() {
   std::string image_data;
   ReadFileToString(path_, &image_data);
-  ImageDecoder::StartWithOptions(this, image_data,
-                                 ImageDecoder::ROBUST_JPEG_CODEC, false);
+  const ImageDecoder::ImageCodec codec =
+      (path_.Extension() == FILE_PATH_LITERAL(".jpg")
+           ? ImageDecoder::ROBUST_JPEG_CODEC
+           : ImageDecoder::ROBUST_PNG_CODEC);
+  ImageDecoder::StartWithOptions(this, image_data, codec, false);
   run_loop_.Run();
   return std::move(decoded_image_);
 }