Auto merge of #23748 - saschanaz:default-dict, r=Manishearth

Sync WebIDL.py with gecko

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The new change requires default dictionary value for optional dictionary-type arguments.

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- [ ] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #23703

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- [x] There are tests for these changes

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1 files changed, 1 insertions, 1 deletions

diff --git a/components/script/dom/webidls/FormDataEvent.webidl b/components/script/dom/webidls/FormDataEvent.webidl
index d34f57b3a09..e478a33a729 100644
--- a/components/script/dom/webidls/FormDataEvent.webidl
+++ b/components/script/dom/webidls/FormDataEvent.webidl
@@ -4,7 +4,7 @@
 
 // https://html.spec.whatwg.org/multipage/#the-formdataevent-interface
 [Exposed=Window,
- Constructor(DOMString type, optional FormDataEventInit eventInitDict)]
+ Constructor(DOMString type, optional FormDataEventInit eventInitDict = {})]
 interface FormDataEvent : Event {
   readonly attribute FormData formData;
 };