Add SkColorToSRGBNSColor to skia_mac_utils

When WCS is enabled, the sRGB color space is the default color space for
Windows [1] and for CSS3 rgb values [2]. Using
SkColorToCalibratedNSColor results in a different (typically ligher)
color when used in Quartz drawing versus a web page, or for color
constants from designers.

This adds SkColorToSRGBNSColor to convert an SkColor value specified in
the sRGB color space to an NSColor.

[1] http://msdn.microsoft.com/en-us/library/windows/hardware/gg487409.aspx
[2] http://www.w3.org/TR/css3-color/#rgb-color

BUG=138633,  254361

Review URL: https://chromiumcodereview.appspot.com/17834003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@209101 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 15 insertions, 1 deletions

diff --git a/skia/ext/skia_utils_mac.h b/skia/ext/skia_utils_mac.h
index 40eb6d4..e6f7b35 100644
--- a/skia/ext/skia_utils_mac.h
+++ b/skia/ext/skia_utils_mac.h
@@ -68,9 +68,11 @@ SK_API CGColorRef CGColorCreateFromSkColor(SkColor color);
 // conversion. Only valid for colors in calibrated and device color spaces.
 SK_API SkColor NSDeviceColorToSkColor(NSColor* color);
 
-// Converts ARGB to NSColor.
+// Converts ARGB in the specified color space to NSColor.
+// Prefer sRGB over calibrated colors.
 SK_API NSColor* SkColorToCalibratedNSColor(SkColor color);
 SK_API NSColor* SkColorToDeviceNSColor(SkColor color);
+SK_API NSColor* SkColorToSRGBNSColor(SkColor color);
 
 // Converts a CGImage to a SkBitmap.
 SK_API SkBitmap CGImageToSkBitmap(CGImageRef image);
diff --git a/skia/ext/skia_utils_mac.mm b/skia/ext/skia_utils_mac.mm
index 4d1ce00..213bb00 100644
--- a/skia/ext/skia_utils_mac.mm
+++ b/skia/ext/skia_utils_mac.mm
@@ -173,6 +173,18 @@ NSColor* SkColorToDeviceNSColor(SkColor color) {
                                alpha:SkColorGetA(color) / 255.0];
 }
 
+NSColor* SkColorToSRGBNSColor(SkColor color) {
+  const CGFloat components[] = {
+    SkColorGetR(color) / 255.0,
+    SkColorGetG(color) / 255.0,
+    SkColorGetB(color) / 255.0,
+    SkColorGetA(color) / 255.0
+  };
+  return [NSColor colorWithColorSpace:[NSColorSpace sRGBColorSpace]
+                           components:components
+                                count:4];
+}
+
 SkBitmap CGImageToSkBitmap(CGImageRef image) {
   if (!image)
     return SkBitmap();