Make tab/tabstrip high density compatible

ui/gfx/image/image_skia_operations.h

+// 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.
+
+#ifndef UI_GFX_IMAGESKIA_OPERATIONS_H_
+#define UI_GFX_IMAGESKIA_OPERATIONS_H_
+#pragma once
+
+#include "base/gtest_prod_util.h"
+#include "ui/base/ui_export.h"
+
+namespace gfx {
+class ImageSkia;
+
+class UI_EXPORT ImageSkiaOperations {
+ public:
+  // Create an image that is a blend of two others. The alpha argument
+  // specifies the opacity of the second imag. The provided image must
+  // use the kARGB_8888_Config config and be of equal dimensions.
+  static ImageSkia CreateBlendedImage(const ImageSkia& first,
+                                      const ImageSkia& second,
+                                      double alpha);
+
+  // Create an image that is the original image masked out by the mask defined
+  // in the alpha image. The images must use the kARGB_8888_Config config and
+  // be of equal dimensions.
+  static ImageSkia CreateMaskedImage(const ImageSkia& first,
+                                     const ImageSkia& alpha);
+
+  // Create an image that is cropped from another image. This is special
+  // because it tiles the original image, so your coordinates can extend
+  // outside the bounds of the original image.
+  static ImageSkia CreateTiledImage(const ImageSkia& image,
+                                    int src_x, int src_y,
+                                    int dst_w, int dst_h);
+
+ private:
+  ImageSkiaOperations();  // Class for scoping only.
+};
+
+}
+
+#endif  // UI_GFX_IMAGESKIA_OPERATIONS_H_