Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

external/aspnetwebstack/src/Microsoft.Web.Mvc/CssExtensions.cs

@@ -0,0 +1,44 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
+
+using System;
+using System.Web.Mvc;
+using Microsoft.Web.Mvc.Properties;
+
+namespace Microsoft.Web.Mvc
+{
+    public static class CssExtensions
+    {
+        public static MvcHtmlString Css(this HtmlHelper helper, string file)
+        {
+            return Css(helper, file, null);
+        }
+
+        public static MvcHtmlString Css(this HtmlHelper helper, string file, string mediaType)
+        {
+            if (String.IsNullOrEmpty(file))
+            {
+                throw new ArgumentException(MvcResources.Common_NullOrEmpty, "file");
+            }
+
+            string src;
+            if (ScriptExtensions.IsRelativeToDefaultPath(file))
+            {
+                src = "~/Content/" + file;
+            }
+            else
+            {
+                src = file;
+            }
+
+            TagBuilder linkTag = new TagBuilder("link");
+            linkTag.MergeAttribute("type", "text/css");
+            linkTag.MergeAttribute("rel", "stylesheet");
+            if (mediaType != null)
+            {
+                linkTag.MergeAttribute("media", mediaType);
+            }
+            linkTag.MergeAttribute("href", UrlHelper.GenerateContentUrl(src, helper.ViewContext.HttpContext));
+            return MvcHtmlString.Create(linkTag.ToString(TagRenderMode.SelfClosing));
+        }
+    }
+}