Auto merge of #25447 - teapotd:form-validation, r=jdm

Form constraint validation

It's almost done, there are few things remaining:

- ~Range underflow, range overflow and step mismatch implementation require #25405~
- ~There are some test failures due to missing DOM parts (#25003)~
- ~`pattern` attribute uses JS regexp syntax. Currently I used regex crate, but it's probably incompatible. Should we use SpiderMonkey's regexp via jsapi?~
- Currently validation errors are reported using `println!`. Are there any better options?
- ~["While the user interface is representing input that the user agent cannot convert to punycode, the control is suffering from bad input."](https://html.spec.whatwg.org/multipage/#e-mail-state-(type%3Demail)%3Asuffering-from-bad-input)~

r? @jdm

---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #11444
- [x] There are tests for these changes

1 files changed, 5 insertions, 5 deletions

diff --git a/components/script/dom/webidls/HTMLObjectElement.webidl b/components/script/dom/webidls/HTMLObjectElement.webidl
index c8779cd9921..9d60c4a4f92 100644
--- a/components/script/dom/webidls/HTMLObjectElement.webidl
+++ b/components/script/dom/webidls/HTMLObjectElement.webidl
@@ -25,12 +25,12 @@ interface HTMLObjectElement : HTMLElement {
   //readonly attribute Document? contentDocument;
   //readonly attribute WindowProxy? contentWindow;
 
-  //readonly attribute boolean willValidate;
+  readonly attribute boolean willValidate;
   readonly attribute ValidityState validity;
-  //readonly attribute DOMString validationMessage;
-  //boolean checkValidity();
-  //boolean reportValidity();
-  //void setCustomValidity(DOMString error);
+  readonly attribute DOMString validationMessage;
+  boolean checkValidity();
+  boolean reportValidity();
+  void setCustomValidity(DOMString error);
 
   //legacycaller any (any... arguments);