Add support for transparent/translucent pixels in the user image

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_USERS_AVATAR_USER_IMAGE_MANAGER_TEST_UTIL_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_USERS_AVATAR_USER_IMAGE_MANAGER_TEST_UTIL_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/run_loop.h"
 #include "chrome/browser/image_decoder.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace gfx {
 class ImageSkia;
 }
 
 namespace chromeos {
 namespace test {
 
 extern const char kUserAvatarImage1RelativePath[];
 extern const char kUserAvatarImage2RelativePath[];
+// Points to a png file with transparent pixels.
+extern const char kUserAvatarImage3RelativePath[];
 
 // Returns |true| if the two given images are pixel-for-pixel identical.
 bool AreImagesEqual(const gfx::ImageSkia& first, const gfx::ImageSkia& second);
 
 class ImageLoader : public ImageDecoder::ImageRequest {
  public:
   explicit ImageLoader(const base::FilePath& path);
   ~ImageLoader() override;
 
   std::unique_ptr<gfx::ImageSkia> Load();
 
   // ImageDecoder::ImageRequest:
   void OnImageDecoded(const SkBitmap& decoded_image) override;
   void OnDecodeImageFailed() override;
 
  private:
   base::FilePath path_;
   base::RunLoop run_loop_;
 
   std::unique_ptr<gfx::ImageSkia> decoded_image_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageLoader);
 };
 
 }  // namespace test
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_USERS_AVATAR_USER_IMAGE_MANAGER_TEST_UTIL_H_