--- a/dom/bindings/test/test_dom_xrays.html
+++ b/dom/bindings/test/test_dom_xrays.html
@@ -166,17 +166,17 @@ function test()
   ok(Object.isFrozen(languages2.wrappedJSObject),
      ".languages should still be a frozen array underneath");
   isnot(languages1, languages2, "Must have distinct arrays");
   isnot(languages1, languages2.wrappedJSObject,
         "Must have distinct arrays no matter how we slice it");
 
   // Check that DataTransfer's .types has the hack to alias contains()
   // to includes().
-  var dataTransfer = new win.DataTransfer("foo", true);
+  var dataTransfer = new win.DataTransfer();
   is(dataTransfer.types.contains, dataTransfer.types.includes,
      "Should have contains() set up as an alias to includes()");
   // Waive Xrays on the dataTransfer itself, since the .types we get is
   // different over Xrays vs not.
   is(dataTransfer.wrappedJSObject.types.contains, undefined,
      "Underlying object should not have contains() set up as an alias to " +
      "includes()");
 

deleted file mode 100644
--- a/testing/web-platform/meta/FileAPI/file/send-file-form-iso-2022-jp.tentative.html.ini
+++ /dev/null
@@ -1,19 +0,0 @@
-[send-file-form-iso-2022-jp.tentative.html]
-  [Upload file-for-upload-in-form.txt (ASCII) in ISO-2022-JP form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-.txt (x-user-defined) in ISO-2022-JP form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-☺😂.txt (windows-1252) in ISO-2022-JP form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-★星★.txt (JIS X 0201 and JIS X 0208) in ISO-2022-JP form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-☺😂.txt (Unicode) in ISO-2022-JP form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-ABC~‾¥≈¤･・•∙·☼★星🌟星★☼·∙•・･¤≈¥‾~XYZ.txt (Unicode) in ISO-2022-JP form]
-    expected: FAIL
-

deleted file mode 100644
--- a/testing/web-platform/meta/FileAPI/file/send-file-form-utf-8.html.ini
+++ /dev/null
@@ -1,19 +0,0 @@
-[send-file-form-utf-8.html]
-  [Upload file-for-upload-in-form.txt (ASCII) in UTF-8 form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-.txt (x-user-defined) in UTF-8 form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-☺😂.txt (windows-1252) in UTF-8 form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-★星★.txt (JIS X 0201 and JIS X 0208) in UTF-8 form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-☺😂.txt (Unicode) in UTF-8 form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-ABC~‾¥≈¤･・•∙·☼★星🌟星★☼·∙•・･¤≈¥‾~XYZ.txt (Unicode) in UTF-8 form]
-    expected: FAIL
-

deleted file mode 100644
--- a/testing/web-platform/meta/FileAPI/file/send-file-form-windows-1252.tentative.html.ini
+++ /dev/null
@@ -1,19 +0,0 @@
-[send-file-form-windows-1252.tentative.html]
-  [Upload file-for-upload-in-form.txt (ASCII) in windows-1252 form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-.txt (x-user-defined) in windows-1252 form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-☺😂.txt (windows-1252) in windows-1252 form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-★星★.txt (JIS X 0201 and JIS X 0208) in windows-1252 form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-☺😂.txt (Unicode) in windows-1252 form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-ABC~‾¥≈¤･・•∙·☼★星🌟星★☼·∙•・･¤≈¥‾~XYZ.txt (Unicode) in windows-1252 form]
-    expected: FAIL
-

deleted file mode 100644
--- a/testing/web-platform/meta/FileAPI/file/send-file-form-x-user-defined.tentative.html.ini
+++ /dev/null
@@ -1,19 +0,0 @@
-[send-file-form-x-user-defined.tentative.html]
-  [Upload file-for-upload-in-form.txt (ASCII) in x-user-defined form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-.txt (x-user-defined) in x-user-defined form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-☺😂.txt (windows-1252) in x-user-defined form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-★星★.txt (JIS X 0201 and JIS X 0208) in x-user-defined form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-☺😂.txt (Unicode) in x-user-defined form]
-    expected: FAIL
-
-  [Upload file-for-upload-in-form-ABC~‾¥≈¤･・•∙·☼★星🌟星★☼·∙•・･¤≈¥‾~XYZ.txt (Unicode) in x-user-defined form]
-    expected: FAIL
-

deleted file mode 100644
--- a/testing/web-platform/meta/FileAPI/file/send-file-form.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[send-file-form.html]
-  [Upload file-for-upload-in-form.txt (ASCII) in UTF-8 form]
-    expected: FAIL
-

--- a/testing/web-platform/meta/html/dom/interfaces.https.html.ini
+++ b/testing/web-platform/meta/html/dom/interfaces.https.html.ini
@@ -1077,19 +1077,16 @@
     expected: FAIL
 
   [OffscreenCanvasRenderingContext2D interface: operation arc(unrestricted double, unrestricted double, unrestricted double, unrestricted double, unrestricted double, boolean)]
     expected: FAIL
 
   [OffscreenCanvasRenderingContext2D interface: operation ellipse(unrestricted double, unrestricted double, unrestricted double, unrestricted double, unrestricted double, unrestricted double, unrestricted double, boolean)]
     expected: FAIL
 
-  [DataTransfer interface object length]
-    expected: FAIL
-
   [Window interface: attribute oncancel]
     expected: FAIL
 
   [Window interface: attribute oncuechange]
     expected: FAIL
 
   [Window interface: attribute onsecuritypolicyviolation]
     expected: FAIL

deleted file mode 100644
--- a/testing/web-platform/meta/html/editing/dnd/datastore/datatransfer-types.html.ini
+++ /dev/null
@@ -1,13 +0,0 @@
-[datatransfer-types.html]
-  [type's state on DataTransfer creation]
-    expected: FAIL
-
-  [Relationship between types and items]
-    expected: FAIL
-
-  [type's identity]
-    expected: FAIL
-
-  [Verify type is a read-only attribute]
-    expected: FAIL
-

deleted file mode 100644
--- a/testing/web-platform/meta/html/semantics/forms/form-submission-0/submit-file.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[submit-file.sub.html]
-  [Posting a File]
-    expected: FAIL
-

--- a/toolkit/content/tests/chrome/window_browser_drop.xul
+++ b/toolkit/content/tests/chrome/window_browser_drop.xul
@@ -26,17 +26,17 @@ function dropOnRemoteBrowserAsync(browse
         let onload = function() {
           content.window.removeEventListener("load", onload);
           resolve();
         };
         content.window.addEventListener("load", onload);
       });
     }
 
-    let dataTransfer = new content.DataTransfer("dragstart", false);
+    let dataTransfer = new content.DataTransfer();
     for (let i = 0; i < data.length; i++) {
       let types = data[i];
       for (let j = 0; j < types.length; j++) {
         dataTransfer.mozSetDataAt(types[j].type, types[j].data, i);
       }
     }
     let event = content.document.createEvent("DragEvent");
     event.initDragEvent("drop", true, true, content, 0, 0, 0, 0, 0,
@@ -161,28 +161,16 @@ async function dropLinksOnBrowser(browse
                     [ { url: "http://www.mozilla.org/",
                         name: "Mozilla.org" },
                       { url: "http://www.example.com/",
                         name: "Example.com" } ],
                     [ [ { type: "text/x-moz-url",
                           data: "http://www.mozilla.org/\nMozilla.org\nhttp://www.example.com/\nExample.com" } ] ],
                     "text/x-moz-url with 2 URLs drop on browser " + type);
 
-  // Dropping multiple items should open multiple pages.
-  await expectLink(browser,
-                    [ { url: "http://www.example.com/",
-                        name: "Example.com" },
-                      { url: "http://www.mozilla.org/",
-                        name: "http://www.mozilla.org/" }],
-                    [ [ { type: "text/x-moz-url",
-                          data: "http://www.example.com/\nExample.com" } ],
-                      [ { type: "text/plain",
-                          data: "http://www.mozilla.org/" } ] ],
-                    "text/x-moz-url and text/plain drop on browser " + type);
-
   // Dropping single item with multiple types should open single page.
   await expectLink(browser,
                     [ { url: "http://www.example.org/",
                         name: "Example.com" } ],
                     [ [ { type: "text/plain",
                           data: "http://www.mozilla.org/" },
                         { type: "text/x-moz-url",
                           data: "http://www.example.org/\nExample.com" } ] ],