Share a common alpha value used for displaying disabled state in Harmony

ui/gfx/color_palette.h

 // Copyright 2015 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_COLOR_PALETTE_H_
 #define UI_GFX_COLOR_PALETTE_H_
 
 #include "third_party/skia/include/core/SkColor.h"
 
 namespace gfx {
 
 // A placeholder value for unset colors. This should never be visible and is red
 // as a visual flag for misbehaving code.
 constexpr SkColor kPlaceholderColor = SK_ColorRED;
 
 const SkColor kChromeIconGrey = SkColorSetRGB(0x5A, 0x5A, 0x5A);
 
 // The number refers to the shade of darkness. Each color in the MD
 // palette ranges from 100-900.
 const SkColor kGoogleBlue300 = SkColorSetRGB(0x7B, 0xAA, 0xF7);
 const SkColor kGoogleBlue500 = SkColorSetRGB(0x42, 0x85, 0xF4);
 const SkColor kGoogleBlue700 = SkColorSetRGB(0x33, 0x67, 0xD6);
 const SkColor kGoogleRed300 = SkColorSetRGB(0xE6, 0x7C, 0x73);
 const SkColor kGoogleRed700 = SkColorSetRGB(0xC5, 0x39, 0x29);
 const SkColor kGoogleGreen300 = SkColorSetRGB(0x57, 0xBB, 0x8A);
 const SkColor kGoogleGreen700 = SkColorSetRGB(0x0B, 0x80, 0x43);
 const SkColor kGoogleYellow300 = SkColorSetRGB(0xF7, 0xCB, 0x4D);
 const SkColor kGoogleYellow700 = SkColorSetRGB(0xF0, 0x93, 0x00);
 
+// An alpha value for designating a control's disabled state. In specs this is
+// sometimes listed as 0.38a.
+const SkAlpha kDisabledControlAlpha = 0x61;
+
 }  // namespace gfx
 
 #endif  // UI_GFX_COLOR_PALETTE_H_