Round color values in AlphaBlend() as we already do in HSLShift().

ui/gfx/color_utils.cc

 // 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 "ui/gfx/color_utils.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <cmath>
@@ skipping 132 matching lines @@
     else
       light = static_cast<uint8_t>(SkDoubleToFixed(lightness) >> 8);
 
     return SkColorSetARGB(alpha, light, light, light);
   }
 
   double temp2 = (lightness < 0.5) ?
       (lightness * (1.0 + saturation)) :
       (lightness + saturation - (lightness * saturation));
   double temp1 = 2.0 * lightness - temp2;
-  return SkColorSetARGB(alpha,
-      calcHue(temp1, temp2, hue + 1.0 / 3.0),
-      calcHue(temp1, temp2, hue),
-      calcHue(temp1, temp2, hue - 1.0 / 3.0));
+  return SkColorSetARGB(alpha, calcHue(temp1, temp2, hue + 1.0 / 3.0),
+                        calcHue(temp1, temp2, hue),
+                        calcHue(temp1, temp2, hue - 1.0 / 3.0));
 }
 
 bool IsWithinHSLRange(const HSL& hsl,
                       const HSL& lower_bound,
                       const HSL& upper_bound) {
   DCHECK(hsl.h >= 0 && hsl.h <= 1) << hsl.h;
   DCHECK(hsl.s >= 0 && hsl.s <= 1) << hsl.s;
   DCHECK(hsl.l >= 0 && hsl.l <= 1) << hsl.l;
   DCHECK(lower_bound.h < 0 || upper_bound.h < 0 ||
          (lower_bound.h <= 1 && upper_bound.h <= lower_bound.h + 1))
@@ skipping 113 matching lines @@
   double f_weight = f_alpha * alpha / normalizer;
   double b_weight = b_alpha * (255 - alpha) / normalizer;
 
   double r = (SkColorGetR(foreground) * f_weight +
               SkColorGetR(background) * b_weight) / 255.0;
   double g = (SkColorGetG(foreground) * f_weight +
               SkColorGetG(background) * b_weight) / 255.0;
   double b = (SkColorGetB(foreground) * f_weight +
               SkColorGetB(background) * b_weight) / 255.0;
 
-  return SkColorSetARGB(static_cast<int>(normalizer),
-                        static_cast<int>(r),
-                        static_cast<int>(g),
-                        static_cast<int>(b));
+  return SkColorSetARGB(static_cast<int>(std::round(normalizer)),
+                        static_cast<int>(std::round(r)),
+                        static_cast<int>(std::round(g)),
+                        static_cast<int>(std::round(b)));
 }
 
 bool IsDark(SkColor color) {
   return GetLuminanceForColor(color) < 128;
 }
 
 SkColor BlendTowardOppositeLuminance(SkColor color, SkAlpha alpha) {
   return AlphaBlend(IsDark(color) ? SK_ColorWHITE : SK_ColorBLACK, color,
                     alpha);
 }
 
 SkColor GetReadableColor(SkColor foreground, SkColor background) {
   const SkColor foreground2 = LumaInvertColor(foreground);
   const double background_luminance = RelativeLuminance(background);
   return (ContrastRatio(RelativeLuminance(foreground), background_luminance) >=
           ContrastRatio(RelativeLuminance(foreground2), background_luminance)) ?
       foreground : foreground2;
 }
 
 SkColor InvertColor(SkColor color) {
-  return SkColorSetARGB(
-      SkColorGetA(color),
-      255 - SkColorGetR(color),
-      255 - SkColorGetG(color),
-      255 - SkColorGetB(color));
+  return SkColorSetARGB(SkColorGetA(color), 255 - SkColorGetR(color),
+                        255 - SkColorGetG(color), 255 - SkColorGetB(color));
 }
 
 SkColor GetSysSkColor(int which) {
 #if defined(OS_WIN)
   return skia::COLORREFToSkColor(GetSysColor(which));
 #else
   NOTIMPLEMENTED();
   return SK_ColorLTGRAY;
 #endif
 }
@@ skipping 11 matching lines @@
   if (IsDark(text_color)) {
     // For black text, this comes out to kChromeIconGrey.
     return color_utils::AlphaBlend(SK_ColorWHITE, text_color,
                                    SkColorGetR(gfx::kChromeIconGrey));
   }
   // The dimming is less dramatic when darkening a light color.
   return color_utils::AlphaBlend(SK_ColorBLACK, text_color, 0x33);
 }
 
 }  // namespace color_utils