Update notification text colors to match spec.

ui/message_center/message_center_style.cc

Index: ui/message_center/message_center_style.cc
diff --git a/ui/message_center/message_center_style.cc b/ui/message_center/message_center_style.cc
index 36205e27407d065cf20d46925f37ae87bff6d071..67985fdef4cd4b64e96b4ec7b9d0f539ffe44a69 100644
--- a/ui/message_center/message_center_style.cc
+++ b/ui/message_center/message_center_style.cc
@@ -42,8 +42,8 @@ const int kMessageLineHeight = 18;
 // Colors.
 const SkColor kNotificationBackgroundColor = SkColorSetRGB(255, 255, 255);
 const SkColor kLegacyIconBackgroundColor = SkColorSetRGB(0xf5, 0xf5, 0xf5);
-const SkColor kRegularTextColor = SkColorSetRGB(0x22, 0x22, 0x22);
-const SkColor kDimTextColor = SkColorSetRGB(0x66, 0x66, 0x66);
+const SkColor kRegularTextColor = SkColorSetRGB(0x33, 0x33, 0x33);
+const SkColor kDimTextColor = SkColorSetRGB(0x7f, 0x7f, 0x7f);
 const SkColor kFocusBorderColor = SkColorSetRGB(64, 128, 250);
 
 // Limits.