Tidy finds WebIDLs with no spec.

Closes #6689

components/script/dom/webidls/BrowserElement.webidl

@@ -4,6 +4,8 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+// https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/browser
+
 callback BrowserElementNextPaintEventCallback = void ();
 
 //dictionary BrowserElementDownloadOptions {

components/script/dom/webidls/CanvasPattern.webidl

@@ -3,6 +3,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+// https://html.spec.whatwg.org/multipage/scripting.html#canvaspattern
+
 interface CanvasPattern {
   //void setTransform(SVGMatrix matrix);
 };

components/script/dom/webidls/ErrorEvent.webidl

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+// https://html.spec.whatwg.org/multipage/webappapis.html#the-errorevent-interface 
+
 [Constructor(DOMString type, optional ErrorEventInit eventInitDict)/*, Exposed=(Window,Worker)*/]
 interface ErrorEvent : Event {
   readonly attribute DOMString message;

components/script/dom/webidls/HTMLCollection.webidl

@@ -3,6 +3,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+// http://www.w3.org/TR/DOM-Level-2-HTML/html.html#ID-75708506
+
 interface HTMLCollection {
   readonly attribute unsigned long length;
   getter Element? item(unsigned long index);

components/script/dom/webidls/NamedNodeMap.webidl

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+// https://dom.spec.whatwg.org/#interface-namednodemap
+
 interface NamedNodeMap {
   readonly attribute unsigned long length;
   getter Attr? item(unsigned long index);

components/script/dom/webidls/ServoHTMLParser.webidl

@@ -3,6 +3,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+// This interface is entirely internal to Servo, and should not be accessible to
+// web pages.
+
 // FIXME: find a better way to hide this from content (#3688)
 [NoInterfaceObject]
 interface ServoHTMLParser {

components/script/dom/webidls/TestBinding.webidl

@@ -2,6 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+// This interface is entirely internal to Servo, and should not be accessible to
+// web pages.
+
 enum TestEnum { "", "foo", "bar" };
 
 dictionary TestDictionary {

components/script/dom/webidls/TestBindingProxy.webidl

@@ -9,6 +9,9 @@
  *
  */
 
+// This interface is entirely internal to Servo, and should not be accessible to
+// web pages.
+
 interface TestBindingProxy : TestBinding {
 
   getter DOMString getNamedItem(DOMString name);

components/script/dom/webidls/WebSocket.webidl

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+// https://w3c.github.io/websockets/#the-websocket-interface
+
 enum BinaryType { "blob", "arraybuffer" };
 
 [Constructor(DOMString url)]