Implement input type=color UI (mac part)

chrome/browser/ui/cocoa/color_utils.mm

+// Copyright (c) 2011 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 "chrome/browser/ui/cocoa/color_utils.h"
+
+#include <algorithm>
+
+WebKit::WebColor WebColorFromNSColor(NSColor *color) {
+  CGFloat r, g, b, a;
+  [color getRed:&r green:&g blue:&b alpha:&a];
+
+  return
+      std::max(0, std::min(static_cast<int>(lroundf(255.0f * a)), 255)) << 24 |
+      std::max(0, std::min(static_cast<int>(lroundf(255.0f * r)), 255)) << 16 |
+      std::max(0, std::min(static_cast<int>(lroundf(255.0f * g)), 255)) << 8  |
+      std::max(0, std::min(static_cast<int>(lroundf(255.0f * b)), 255));
+}
+
+NSColor *NSColorFromWebColor(WebKit::WebColor color) {
+  uint8 a = (color >> 24) & 0xFF;
+  uint8 r = (color >> 16) & 0xFF;
+  uint8 g = (color >>  8) & 0xFF;
+  uint8 b = (color >>  0) & 0xFF;
+  return [NSColor colorWithDeviceRed:static_cast<CGFloat>(r) / 255.0
+                               green:static_cast<CGFloat>(g) / 255.0
+                                blue:static_cast<CGFloat>(b) / 255.0
+                               alpha:static_cast<CGFloat>(a) / 255.0];
+}