Also moved LinkText to its own file so the chat could reuse it (ProfileHeader's private class ProfileLink also still inherits from this, though)

osu.Game/Graphics/Sprites/OsuLinkSpriteText.cs

@@ -0,0 +1,55 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using OpenTK.Graphics;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Input;
+using osu.Game.Graphics.Containers;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace osu.Game.Graphics.Sprites
+{
+    public class OsuLinkSpriteText : OsuSpriteText
+    {
+        private readonly OsuHoverContainer content;
+
+        public override bool HandleInput => content.Action != null;
+
+        protected override Container<Drawable> Content => content ?? (Container<Drawable>)this;
+
+        protected override IEnumerable<Drawable> FlowingChildren => Children;
+
+        private string url;
+
+        public string Url
+        {
+            get
+            {
+                return url;
+            }
+            set
+            {
+                if (value != null)
+                {
+                    url = value;
+                    content.Action = () => Process.Start(value);
+                }
+            }
+        }
+
+        public OsuLinkSpriteText()
+        {
+            AddInternal(content = new OsuHoverContainer
+            {
+                AutoSizeAxes = Axes.Both,
+            });
+        }
+    }
+}