Merge 25340 - Add functions to alphablend two colors and pick the more readab...

app/gfx/color_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 APP_GFX_COLOR_UTILS_H_
 #define APP_GFX_COLOR_UTILS_H_
 
 #include "third_party/skia/include/core/SkColor.h"
 
 class SkBitmap;
@@ skipping 34 matching lines @@
 
 // Gets a color representing a bitmap. The definition of "representing" is the
 // average color in the bitmap. The color returned is modified to have the
 // specified alpha.
 SkColor GetAverageColorOfFavicon(SkBitmap* bitmap, SkAlpha alpha);
 
 // Builds a histogram based on the Y' of the Y'UV representation of
 // this image.
 void BuildLumaHistogram(SkBitmap* bitmap, int histogram[256]);
 
-// Create a color from a base color and a specific alpha value.
-SkColor SetColorAlpha(SkColor c, SkAlpha alpha);
+// Returns a blend of the supplied colors, ranging from |background| (for
+// |alpha| == 0) to |foreground| (for |alpha| == 255).
+SkColor AlphaBlend(SkColor foreground, SkColor background, SkAlpha alpha);
+
+// Given two possible foreground colors, return the one that is more readable
+// over |background|.
+SkColor PickMoreReadableColor(SkColor foreground1,
+                              SkColor foreground2,
+                              SkColor background);
 
 // Gets a Windows system color as a SkColor
 SkColor GetSysSkColor(int which);
 
 } // namespace color_utils
 
 #endif  // #ifndef APP_GFX_COLOR_UTILS_H_