Basic pixel tests for cc

cc/test/pixel_test_utils.h

Index: cc/test/pixel_test_utils.h
diff --git a/cc/test/pixel_test_utils.h b/cc/test/pixel_test_utils.h
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index 0000000000000000000000000000000000000000..93367d867f0fd05865b293620f45f8729c303f10
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+++ b/cc/test/pixel_test_utils.h
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+// Copyright (c) 2012 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.
+
+#include "base/file_path.h"
+
+class SkBitmap;
+
+namespace cc {
+namespace test {
+
+// Encodes a bitmap into a PNG and write to disk. Returns true on success. The
+// parent directory does not have to exist.
+bool WritePNGFile(const SkBitmap& bitmap, const FilePath& file_path);
+
+// Reads and decodes a PNG image to a bitmap. Returns true on success. The PNG
+// should have been encoded using |gfx::PNGCodec::Encode|.
+bool ReadPNGFile(const FilePath& file_path, SkBitmap* bitmap);
+
+// Compares with a PNG file on disk, and returns true if it is the same as
+// the given image. |ref_img_path| is absolute.
+bool IsSameAsPNGFile(const SkBitmap& gen_bmp, FilePath ref_img_path);
+
+}  // namespace test
+}  // namespace cc