Make some updates to BM bar for MD.

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 <math.h>
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
@@ skipping 60 matching lines @@
   return (foreground_luminance > background_luminance) ?
       (foreground_luminance / background_luminance) :
       (background_luminance / foreground_luminance);
 }
 
 }  // namespace
 
 
 // ----------------------------------------------------------------------------
 
+double GetContrastRatio(SkColor color_a, SkColor color_b) {
+  return ContrastRatio(RelativeLuminance(color_a), RelativeLuminance(color_b));
+}
+
 unsigned char GetLuminanceForColor(SkColor color) {
   return base::saturated_cast<unsigned char>(
       (0.3 * SkColorGetR(color)) +
       (0.59 * SkColorGetG(color)) +
       (0.11 * SkColorGetB(color)));
 }
 
 double RelativeLuminance(SkColor color) {
   return (0.2126 * ConvertSRGB(SkColorGetR(color))) +
          (0.7152 * ConvertSRGB(SkColorGetG(color))) +
@@ skipping 237 matching lines @@
 #endif  // !defined(OS_WIN)
 
 SkColor DeriveDefaultIconColor(SkColor text_color) {
   // For black text, this comes out to gfx::kChromeIconGrey.
   SkColor color = BlendTowardOppositeLuminance(
       text_color, SkColorGetR(gfx::kChromeIconGrey));
   return color;
 }
 
 }  // namespace color_utils