Add bitmap manipulation functions in advance of themes.

skia/ext/skia_utils.h

 // Copyright (c) 2006-2008 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 SKIA_EXT_SKIA_UTILS_H_
 #define SKIA_EXT_SKIA_UTILS_H_
 
 #include "SkColor.h"
 #include "SkShader.h"
 
 namespace skia {
 
 // Creates a vertical gradient shader. The caller owns the shader.
 // Example usage to avoid leaks:
 //   paint.setShader(gfx::CreateGradientShader(0, 10, red, blue))->safeUnref();
 //
 // (The old shader in the paint, if any, needs to be freed, and safeUnref will
 // handle the NULL case.)
 SkShader* CreateGradientShader(int start_point,
                                int end_point,
                                SkColor start_color,
                                SkColor end_color);
 
+// Convert a premultiplied SkColor to a HSL value.
+void SkColorToHSL(SkColor c, float hsl[3]);

[brettw, 2009/04/28 02:49:43]

Since the colors are premultiplied, you should use SkPMColor here, below, and in
image_operations internally when you read the values. That way the
premultiplication aspect of it (which is fine) is self-documenting and
type-checked.

+
+// Convert a HSL color to a premultiplied SkColor.
+SkColor HSLToSKColor(U8CPU alpha, float hsl[3]);
+
 }  // namespace skia
 
 #endif  // SKIA_EXT_SKIA_UTILS_H_