Bug 1412463 - Remove the chromeonly DataTransfer.types.contains function. r=dom-core,emilio,edgar

This was originally added for backwards compatibility for extensions when fixing the DataTransfer.types type.
The extensions are no longer supported.

Differential Revision: https://phabricator.services.mozilla.com/D188330

dom/bindings/Codegen.py

@@ -8960,10 +8960,6 @@ def wrapArgIntoCurrentCompartment(arg, value, isMember=True):
     return wrap
 
 
-def needsContainsHack(m):
-    return m.getExtendedAttribute("ReturnValueNeedsContainsHack")
-
-
 def needsCallerType(m):
     return m.getExtendedAttribute("NeedsCallerType")
 
@@ -9577,23 +9573,6 @@ class CGPerSignatureCall(CGThing):
             # the compartment we do our conversion in but after we've finished
             # the initial conversion into args.rval().
             postConversionSteps = ""
-            if needsContainsHack(self.idlNode):
-                # Define a .contains on the object that has the same value as
-                # .includes; needed for backwards compat in extensions as we
-                # migrate some DOMStringLists to FrozenArray.
-                postConversionSteps += dedent(
-                    """
-                    if (args.rval().isObject() && nsContentUtils::ThreadsafeIsSystemCaller(cx)) {
-                      JS::Rooted<JSObject*> rvalObj(cx, &args.rval().toObject());
-                      JS::Rooted<JS::Value> includesVal(cx);
-                      if (!JS_GetProperty(cx, rvalObj, "includes", &includesVal) ||
-                          !JS_DefineProperty(cx, rvalObj, "contains", includesVal, JSPROP_ENUMERATE)) {
-                        return false;
-                      }
-                    }
-
-                    """
-                )
             if self.idlNode.getExtendedAttribute("Frozen"):
                 assert (
                     self.idlNode.type.isSequence() or self.idlNode.type.isDictionary()
@@ -18883,7 +18862,7 @@ class CGBindingRoot(CGThing):
 
             return (
                 any(
-                    isChromeOnly(a) or needsContainsHack(a) or needsCallerType(a)
+                    isChromeOnly(a) or needsCallerType(a)
                     for a in desc.interface.members
                 )
                 or desc.interface.getExtendedAttribute("ChromeOnly") is not None

dom/bindings/parser/WebIDL.py

@@ -5719,7 +5719,6 @@ class IDLAttribute(IDLInterfaceMember):
             or identifier == "SetterNeedsSubjectPrincipal"
             or identifier == "GetterNeedsSubjectPrincipal"
             or identifier == "NeedsCallerType"
-            or identifier == "ReturnValueNeedsContainsHack"
             or identifier == "BinaryName"
             or identifier == "NonEnumerable"
             or identifier == "BindingTemplate"

dom/bindings/test/test_dom_xrays.html

@@ -198,17 +198,6 @@ function test() {
   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();
-  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()");
-
   // Check that deleters work correctly in the [OverrideBuiltins] case.
   elem = win.document.documentElement;
   var dataset = elem.dataset;

dom/events/test/test_dragstart.html

@@ -61,7 +61,7 @@ function afterDragTests()
   sendMouseEventsForDrag("link");
   sendMouseEventsForDrag("image");
 
-//  disable testing input dragging for now, as it doesn't seem to be testable 
+//  disable testing input dragging for now, as it doesn't seem to be testable
 //  draggable = $("input");
 //  draggable.setSelectionRange(0, 4);
 //  synthesizeMouse(draggable, 8, 8, { type: "mousedown" });
@@ -188,7 +188,7 @@ function test_DataTransfer(dt)
   var types = dt.types;
   ok(Array.isArray(types), "empty types is an Array");
   // The above test fails if we have SpecialPowers.wrap(dt).types instead of dt.types
-  // because chrome consumers get the 'ReturnValueNeedsContainsHack'.
+  // because dt.types will be wrapped and become a proxy.
   // So wrap with special powers after the test
   dt = SpecialPowers.wrap(dt);
   checkTypes(dt, [], 0, "empty");

dom/webidl/DataTransfer.webidl

@@ -19,9 +19,7 @@ interface DataTransfer {
 
   undefined setDragImage(Element image, long x, long y);
 
-  // ReturnValueNeedsContainsHack on .types because lots of extension
-  // code was expecting .contains() back when it was a DOMStringList.
-  [Pure, Cached, Frozen, NeedsCallerType, ReturnValueNeedsContainsHack]
+  [Frozen, Cached, Pure, NeedsCallerType]
   readonly attribute sequence<DOMString> types;
   [Throws, NeedsSubjectPrincipal]
   DOMString getData(DOMString format);