Set referrer for CSS resources

LayoutTests/http/tests/css/resources/css-resources-referrer.css

Index: LayoutTests/http/tests/css/resources/css-resources-referrer.css
diff --git a/LayoutTests/http/tests/css/resources/css-resources-referrer.css b/LayoutTests/http/tests/css/resources/css-resources-referrer.css
new file mode 100644
index 0000000000000000000000000000000000000000..fe3a5e26ed8849d83ba4d1caacd50ad8a88d1a66
--- /dev/null
+++ b/LayoutTests/http/tests/css/resources/css-resources-referrer.css
@@ -0,0 +1,16 @@
+@import url(css-resources-referrer-import.css);
+
+@font-face {
+    font-family: faceInSheet;
+    src: url('referrer-check.php?from=sheet&resource=font');
+}
+
+.imageInSheet {
+    background-image: url('referrer-check.php?from=sheet&resource=image');
+}
+.imageSetInSheet {
+    background-image: -webkit-image-set(
+        url('referrer-check.php?from=sheet&resource=image2') 1x,
+        url('referrer-check.php?from=sheet&resource=image') 2x
+    );
+}