diff --git a/src/test/content/test_document_getElementById.html b/src/test/content/test_document_getElementById.html
index 2617fb2e113..d8430011b33 100644
--- a/src/test/content/test_document_getElementById.html
+++ b/src/test/content/test_document_getElementById.html
@@ -8,104 +8,6 @@
   <script>
     let gBody = document.getElementsByTagName("body")[0];
 
-    // test1: on static page
-    {
-      let foo = document.getElementById("foo");
-      is_not(foo, null, "test-1-0, on static page");
-      is(foo && foo.tagName, "HEAD", "test1-1, on static page");
-      is_a(foo, HTMLHeadElement, "test1-2, on static page");
-
-      let bar = document.getElementById("bar");
-      is_not(bar, null, "test1-3, on static page");
-      is(bar && bar.tagName, "DIV", "test1-4, on static page");
-      is_a(bar, HTMLDivElement, "test1-5, on static page");
-    }
-
-    // test2: scripted element
-    {
-      let TEST_ID = "test";
-      let test = document.createElement("div");
-      test.setAttribute("id", TEST_ID);
-      gBody.appendChild(test);
-
-      // test: appended element
-      let appended = document.getElementById(TEST_ID);
-      is_not(appended, null, "test2-0, appended element");
-      is(appended && appended.tagName, "DIV", "test2-1, appended element");
-      is_a(appended, HTMLDivElement, "test2-2, appended element");
-
-      // test: removed element
-      gBody.removeChild(test);
-      let removed = document.getElementById(TEST_ID);
-      // `document.getElementById()` returns `null` if there is none.
-      // http://www.w3.org/TR/DOM-Level-3-Core/core.html#ID-getElBId
-      // http://dom.spec.whatwg.org/#dom-document-getelementbyid (2013-09-20)
-      is(removed, null, "test2-3, removed element");
-    }
-
-    // test3: update `id` attribute
-    {
-      // setup fixtures.
-      let TEST_ID = "test3";
-      let test = document.createElement("div");
-      test.setAttribute("id", TEST_ID);
-      gBody.appendChild(test);
-
-      // update id
-      let UPDATED_ID = "test3-updated";
-      test.setAttribute("id", UPDATED_ID);
-      let e = document.getElementById(UPDATED_ID);
-      is(e, test, "test3-0, update 'id' attribute.");
-
-      let old = document.getElementById(TEST_ID);
-      is(old, null, "test3-1, the method shouldn't get the element by the old id.");
-
-      // remove id.
-      test.removeAttribute("id");
-      let e2 = document.getElementById(UPDATED_ID);
-      is(e2, null, "test3-2, the method should return null when the passed id is none in document.");
-    }
-
-    // test 4
-    {
-      // Ensure that the id attribute only affects elements present in a document
-      let e = document.createElement('div');
-      e.id = "should-not-exist";
-      is(document.getElementById("should-not-exist"), null, "test 4-0");
-      document.body.appendChild(e);
-      is(document.getElementById("should-not-exist"), e, "test 4-1");
-    }
-
-    // test5: "in tree order, within the context object's tree"
-    // http://dom.spec.whatwg.org/#dom-document-getelementbyid.
-    // we test this in test_document_getElementById_tree_order.html
-
-    // TODO:
-    // test6: innerHTML
-
-    // test 7
-    {
-      // Test that we only cache elements by ID if they're in a document (see #1874).
-      let s = document.createElement("div");
-      s.setAttribute("id", "x");
-      document.createElement("div").appendChild(s);
-      is(document.getElementById("x"), null, "test 7-0");
-    }
-
-    // test 8
-    {
-      let TEST_ID = "test-8"
-      let element = document.createElement("div");
-      element.setAttribute("id", TEST_ID);
-      document.body.appendChild(element);
-      let target = document.getElementById(TEST_ID);
-      is_not(target, null, "test 8-0, getElementById is correct before changing the value");
-
-      element.attributes[0].value = TEST_ID + "-updated";
-      let target2 = document.getElementById(TEST_ID);
-      is(target2, null, "test 8-1, should return null after updated id via Attr.value");
-    }
-
     // Test the assertion with inserting node with child having id into the document (mozilla#2630)
     // This need not to port to WPF-test because this tests servo's internally flags.
     {
diff --git a/src/test/content/test_document_getElementById_tree_order.html b/src/test/content/test_document_getElementById_tree_order.html
deleted file mode 100644
index ccf0c37bb01..00000000000
--- a/src/test/content/test_document_getElementById_tree_order.html
+++ /dev/null
@@ -1,40 +0,0 @@
-<html>
-  <head>
-    <script src="harness.js"></script>
-  </head>
-  <body>
-    <div id="a">
-    </div>
-    <div id="b">
-      <p id="b">P</p>
-      <input id="b" type="submit" value="Submit">
-    </div>
-    <script>
-      {
-        var b = document.getElementById("b");
-        is_a(b, HTMLDivElement);
-        var a = document.getElementById("a");
-        var p = document.createElement("p");
-        p.id = "b";
-        a.appendChild(p);
-        var newB = document.getElementById("b");
-        is_a(newB, HTMLParagraphElement);
-      }
-      {
-        var gbody = document.getElementsByTagName("body")[0];
-        var div = document.createElement("div");
-        div.setAttribute("id", "c");
-        var h1 = document.createElement("h1");
-        h1.setAttribute("id", "c");
-        gbody.appendChild(div);
-        gbody.appendChild(h1);
-        var c = document.getElementById("c");
-        is_a(c, HTMLDivElement);
-        gbody.removeChild(div);
-        var newC = document.getElementById("c");
-        is_a(newC, HTMLHeadingElement);
-      }
-      finish();
-    </script>
-  </body>
-</html>