diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index 8ba03946574..552bfacb867 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -12,16 +12,6 @@ fragment=top != ../html/acid2.html acid2_ref.html
 == acid1_a.html acid1_b.html
 == acid2_noscroll.html acid2_ref_broken.html
 flaky_cpu == append_style_a.html append_style_b.html
-== attr_selector_case_sensitivity.html attr_selector_case_sensitivity_ref.html
-== background_clip_a.html background_clip_ref.html
-== background_external_stylesheet.html background_ref.html
-== background_image_a.html background_image_ref.html
-== background_image_position_a.html background_image_position_ref.html
-== background_none_a.html background_none_b.html
-== background_origin_a.html background_origin_ref.html
-== background_position_a.html background_position_b.html
-== background_position_keyword.html background_position_b.html
-== background_position_percent.html background_position_b.html
 == background_position_shorthand.html background_position_shorthand_ref.html
 == background_repeat_both_a.html background_repeat_both_b.html
 == background_repeat_none_a.html background_repeat_none_b.html
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 6f934c8ca4a..8cd63cc7c26 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -183,6 +183,18 @@
             "url": "/_mozilla/css/attr_exists_selector.html"
           }
         ],
+        "css/attr_selector_case_sensitivity.html": [
+          {
+            "path": "css/attr_selector_case_sensitivity.html",
+            "references": [
+              [
+                "/_mozilla/css/attr_selector_case_sensitivity_ref.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/attr_selector_case_sensitivity.html"
+          }
+        ],
         "css/background.html": [
           {
             "path": "css/background.html",
@@ -195,6 +207,114 @@
             "url": "/_mozilla/css/background.html"
           }
         ],
+        "css/background_clip_a.html": [
+          {
+            "path": "css/background_clip_a.html",
+            "references": [
+              [
+                "/_mozilla/css/background_clip_ref.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/background_clip_a.html"
+          }
+        ],
+        "css/background_external_stylesheet.html": [
+          {
+            "path": "css/background_external_stylesheet.html",
+            "references": [
+              [
+                "/_mozilla/css/background_rust_ref.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/background_external_stylesheet.html"
+          }
+        ],
+        "css/background_image_a.html": [
+          {
+            "path": "css/background_image_a.html",
+            "references": [
+              [
+                "/_mozilla/css/background_image_ref.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/background_image_a.html"
+          }
+        ],
+        "css/background_image_position_a.html": [
+          {
+            "path": "css/background_image_position_a.html",
+            "references": [
+              [
+                "/_mozilla/css/background_image_position_ref.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/background_image_position_a.html"
+          }
+        ],
+        "css/background_none_a.html": [
+          {
+            "path": "css/background_none_a.html",
+            "references": [
+              [
+                "/_mozilla/css/background_none_b.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/background_none_a.html"
+          }
+        ],
+        "css/background_origin_a.html": [
+          {
+            "path": "css/background_origin_a.html",
+            "references": [
+              [
+                "/_mozilla/css/background_origin_ref.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/background_origin_a.html"
+          }
+        ],
+        "css/background_position_a.html": [
+          {
+            "path": "css/background_position_a.html",
+            "references": [
+              [
+                "/_mozilla/css/background_position_b.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/background_position_a.html"
+          }
+        ],
+        "css/background_position_keyword.html": [
+          {
+            "path": "css/background_position_keyword.html",
+            "references": [
+              [
+                "/_mozilla/css/background_position_b.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/background_position_keyword.html"
+          }
+        ],
+        "css/background_position_percent.html": [
+          {
+            "path": "css/background_position_percent.html",
+            "references": [
+              [
+                "/_mozilla/css/background_position_b.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/background_position_percent.html"
+          }
+        ],
         "css/class-namespaces.html": [
           {
             "path": "css/class-namespaces.html",
@@ -1160,6 +1280,18 @@
           "url": "/_mozilla/css/attr_exists_selector.html"
         }
       ],
+      "css/attr_selector_case_sensitivity.html": [
+        {
+          "path": "css/attr_selector_case_sensitivity.html",
+          "references": [
+            [
+              "/_mozilla/css/attr_selector_case_sensitivity_ref.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/attr_selector_case_sensitivity.html"
+        }
+      ],
       "css/background.html": [
         {
           "path": "css/background.html",
@@ -1172,6 +1304,114 @@
           "url": "/_mozilla/css/background.html"
         }
       ],
+      "css/background_clip_a.html": [
+        {
+          "path": "css/background_clip_a.html",
+          "references": [
+            [
+              "/_mozilla/css/background_clip_ref.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/background_clip_a.html"
+        }
+      ],
+      "css/background_external_stylesheet.html": [
+        {
+          "path": "css/background_external_stylesheet.html",
+          "references": [
+            [
+              "/_mozilla/css/background_rust_ref.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/background_external_stylesheet.html"
+        }
+      ],
+      "css/background_image_a.html": [
+        {
+          "path": "css/background_image_a.html",
+          "references": [
+            [
+              "/_mozilla/css/background_image_ref.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/background_image_a.html"
+        }
+      ],
+      "css/background_image_position_a.html": [
+        {
+          "path": "css/background_image_position_a.html",
+          "references": [
+            [
+              "/_mozilla/css/background_image_position_ref.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/background_image_position_a.html"
+        }
+      ],
+      "css/background_none_a.html": [
+        {
+          "path": "css/background_none_a.html",
+          "references": [
+            [
+              "/_mozilla/css/background_none_b.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/background_none_a.html"
+        }
+      ],
+      "css/background_origin_a.html": [
+        {
+          "path": "css/background_origin_a.html",
+          "references": [
+            [
+              "/_mozilla/css/background_origin_ref.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/background_origin_a.html"
+        }
+      ],
+      "css/background_position_a.html": [
+        {
+          "path": "css/background_position_a.html",
+          "references": [
+            [
+              "/_mozilla/css/background_position_b.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/background_position_a.html"
+        }
+      ],
+      "css/background_position_keyword.html": [
+        {
+          "path": "css/background_position_keyword.html",
+          "references": [
+            [
+              "/_mozilla/css/background_position_b.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/background_position_keyword.html"
+        }
+      ],
+      "css/background_position_percent.html": [
+        {
+          "path": "css/background_position_percent.html",
+          "references": [
+            [
+              "/_mozilla/css/background_position_b.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/background_position_percent.html"
+        }
+      ],
       "css/class-namespaces.html": [
         {
           "path": "css/class-namespaces.html",
diff --git a/tests/ref/attr_selector_case_sensitivity.html b/tests/wpt/mozilla/tests/css/attr_selector_case_sensitivity.html
similarity index 87%
rename from tests/ref/attr_selector_case_sensitivity.html
rename to tests/wpt/mozilla/tests/css/attr_selector_case_sensitivity.html
index c4d36db7918..f86ac14b855 100644
--- a/tests/ref/attr_selector_case_sensitivity.html
+++ b/tests/wpt/mozilla/tests/css/attr_selector_case_sensitivity.html
@@ -2,6 +2,7 @@
 <html>
   <head>
     <title>Attribute selector case-sensitivity: [foo=bar] and [foo=bar i]</title>
+    <link rel=match href=attr_selector_case_sensitivity_ref.html>
     <style>
       p[data-foo=Bar] { color: green }
       p[data-foo=bar] { color: red }
diff --git a/tests/ref/attr_selector_case_sensitivity_ref.html b/tests/wpt/mozilla/tests/css/attr_selector_case_sensitivity_ref.html
similarity index 100%
rename from tests/ref/attr_selector_case_sensitivity_ref.html
rename to tests/wpt/mozilla/tests/css/attr_selector_case_sensitivity_ref.html
diff --git a/tests/ref/background_clip_a.html b/tests/wpt/mozilla/tests/css/background_clip_a.html
similarity index 92%
rename from tests/ref/background_clip_a.html
rename to tests/wpt/mozilla/tests/css/background_clip_a.html
index 6a95ec7831a..7f2c8b7f0dd 100644
--- a/tests/ref/background_clip_a.html
+++ b/tests/wpt/mozilla/tests/css/background_clip_a.html
@@ -1,6 +1,7 @@
 <!DOCTYPE html>
 <html>
 <head>
+<link rel=match href=background_clip_ref.html>
 <style>
 div {
     background: green;
diff --git a/tests/ref/background_clip_ref.html b/tests/wpt/mozilla/tests/css/background_clip_ref.html
similarity index 100%
rename from tests/ref/background_clip_ref.html
rename to tests/wpt/mozilla/tests/css/background_clip_ref.html
diff --git a/tests/ref/background_external_stylesheet.html b/tests/wpt/mozilla/tests/css/background_external_stylesheet.html
similarity index 81%
rename from tests/ref/background_external_stylesheet.html
rename to tests/wpt/mozilla/tests/css/background_external_stylesheet.html
index 9465a1b4cae..779ee53213a 100644
--- a/tests/ref/background_external_stylesheet.html
+++ b/tests/wpt/mozilla/tests/css/background_external_stylesheet.html
@@ -3,6 +3,7 @@
 <head>
 <title></title>
 <link rel="stylesheet" href="subdirectory/background_image.css">
+<link rel=match href=background_rust_ref.html>
 </head>
 <body>
 <div class="test" style="width:206px; height:206px;"></div>
diff --git a/tests/ref/background_image_a.html b/tests/wpt/mozilla/tests/css/background_image_a.html
similarity index 85%
rename from tests/ref/background_image_a.html
rename to tests/wpt/mozilla/tests/css/background_image_a.html
index bb7b0434d07..37afc14ca0c 100644
--- a/tests/ref/background_image_a.html
+++ b/tests/wpt/mozilla/tests/css/background_image_a.html
@@ -1,6 +1,7 @@
 <!DOCTYPE html>
 <html>
 <head>
+<link rel=match href=background_image_ref.html>
 <style>
 div {
     background-image: url("test.jpeg");
diff --git a/tests/ref/background_image_position_a.html b/tests/wpt/mozilla/tests/css/background_image_position_a.html
similarity index 87%
rename from tests/ref/background_image_position_a.html
rename to tests/wpt/mozilla/tests/css/background_image_position_a.html
index c11261703d4..f3ff1cc329b 100644
--- a/tests/ref/background_image_position_a.html
+++ b/tests/wpt/mozilla/tests/css/background_image_position_a.html
@@ -1,6 +1,7 @@
 <!DOCTYPE html>
 <html>
     <head>
+        <link rel=match href=background_image_position_ref.html>
         <style type="text/css">
             body {
                 font-family: 'ahem';
diff --git a/tests/ref/background_image_position_ref.html b/tests/wpt/mozilla/tests/css/background_image_position_ref.html
similarity index 100%
rename from tests/ref/background_image_position_ref.html
rename to tests/wpt/mozilla/tests/css/background_image_position_ref.html
diff --git a/tests/ref/background_image_ref.html b/tests/wpt/mozilla/tests/css/background_image_ref.html
similarity index 100%
rename from tests/ref/background_image_ref.html
rename to tests/wpt/mozilla/tests/css/background_image_ref.html
diff --git a/tests/ref/background_none_a.html b/tests/wpt/mozilla/tests/css/background_none_a.html
similarity index 84%
rename from tests/ref/background_none_a.html
rename to tests/wpt/mozilla/tests/css/background_none_a.html
index cbdb5102169..dbbeb9a3779 100644
--- a/tests/ref/background_none_a.html
+++ b/tests/wpt/mozilla/tests/css/background_none_a.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <title>background: none test</title>
+<link rel=match href=background_none_b.html>
 <style>
 #a {
     background: red;
diff --git a/tests/ref/background_none_b.html b/tests/wpt/mozilla/tests/css/background_none_b.html
similarity index 100%
rename from tests/ref/background_none_b.html
rename to tests/wpt/mozilla/tests/css/background_none_b.html
diff --git a/tests/ref/background_origin_a.html b/tests/wpt/mozilla/tests/css/background_origin_a.html
similarity index 93%
rename from tests/ref/background_origin_a.html
rename to tests/wpt/mozilla/tests/css/background_origin_a.html
index 753bacc9145..1bf3ca76391 100644
--- a/tests/ref/background_origin_a.html
+++ b/tests/wpt/mozilla/tests/css/background_origin_a.html
@@ -1,6 +1,7 @@
 <!DOCTYPE html>
 <html>
 <head>
+<link rel=match href=background_origin_ref.html>
 <style>
 #foo1 {
     background: url(400x400_green.png);
diff --git a/tests/ref/background_origin_ref.html b/tests/wpt/mozilla/tests/css/background_origin_ref.html
similarity index 100%
rename from tests/ref/background_origin_ref.html
rename to tests/wpt/mozilla/tests/css/background_origin_ref.html
diff --git a/tests/ref/background_position_a.html b/tests/wpt/mozilla/tests/css/background_position_a.html
similarity index 87%
rename from tests/ref/background_position_a.html
rename to tests/wpt/mozilla/tests/css/background_position_a.html
index 23547b3f6b6..589e1a44ee7 100644
--- a/tests/ref/background_position_a.html
+++ b/tests/wpt/mozilla/tests/css/background_position_a.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <title>You see here a scroll labeled FOOBIE BLETCH.</title>
+<link rel=match href=background_position_b.html>
 <style>
 #foo {
     background: url(400x400_green.png);
diff --git a/tests/ref/background_position_b.html b/tests/wpt/mozilla/tests/css/background_position_b.html
similarity index 100%
rename from tests/ref/background_position_b.html
rename to tests/wpt/mozilla/tests/css/background_position_b.html
diff --git a/tests/ref/background_position_keyword.html b/tests/wpt/mozilla/tests/css/background_position_keyword.html
similarity index 87%
rename from tests/ref/background_position_keyword.html
rename to tests/wpt/mozilla/tests/css/background_position_keyword.html
index 6e7962d0b46..f7a3e1a4d43 100644
--- a/tests/ref/background_position_keyword.html
+++ b/tests/wpt/mozilla/tests/css/background_position_keyword.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <title>You see here a scroll labeled FOOBIE BLETCH.</title>
+<link rel=match href=background_position_b.html>
 <style>
 #foo {
     background: url(400x400_green.png);
diff --git a/tests/ref/background_position_percent.html b/tests/wpt/mozilla/tests/css/background_position_percent.html
similarity index 87%
rename from tests/ref/background_position_percent.html
rename to tests/wpt/mozilla/tests/css/background_position_percent.html
index 3b3ecc77ec0..daf29276e59 100644
--- a/tests/ref/background_position_percent.html
+++ b/tests/wpt/mozilla/tests/css/background_position_percent.html
@@ -2,6 +2,7 @@
 <html>
 <head>
 <title>You see here a scroll labeled FOOBIE BLETCH.</title>
+<link rel=match href=background_position_b.html>
 <style>
 #foo {
     background: url(400x400_green.png);
diff --git a/tests/wpt/mozilla/tests/css/background_rust_ref.html b/tests/wpt/mozilla/tests/css/background_rust_ref.html
new file mode 100644
index 00000000000..81f0d15e1fc
--- /dev/null
+++ b/tests/wpt/mozilla/tests/css/background_rust_ref.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title></title>
+</head>
+<body>
+<img class="test" src="rust-0.png" style="width:206px; height:206px;" />
+</body>
+</html>
diff --git a/tests/ref/line.png b/tests/wpt/mozilla/tests/css/line.png
similarity index 100%
rename from tests/ref/line.png
rename to tests/wpt/mozilla/tests/css/line.png
diff --git a/tests/ref/subdirectory/background_image.css b/tests/wpt/mozilla/tests/css/subdirectory/background_image.css
similarity index 100%
rename from tests/ref/subdirectory/background_image.css
rename to tests/wpt/mozilla/tests/css/subdirectory/background_image.css
diff --git a/tests/wpt/mozilla/tests/css/test.jpeg b/tests/wpt/mozilla/tests/css/test.jpeg
new file mode 100644
index 00000000000..3314a53600b
Binary files /dev/null and b/tests/wpt/mozilla/tests/css/test.jpeg differ