Auto merge of #29455 - 2shiori17:issue-29425, r=mukilan

Implement URLSearchParams's size

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---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #29425

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- [x] There are tests for these changes OR
- [ ] These changes do not require tests because ___

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components/script/dom/urlsearchparams.rs

@@ -91,6 +91,11 @@ impl URLSearchParams {
 }
 
 impl URLSearchParamsMethods for URLSearchParams {
+    // https://url.spec.whatwg.org/#dom-urlsearchparams-size
+    fn Size(&self) -> u32 {
+        self.list.borrow().len() as u32
+    }
+
     // https://url.spec.whatwg.org/#dom-urlsearchparams-append
     fn Append(&self, name: USVString, value: USVString) {
         // Step 1.

components/script/dom/webidls/URLSearchParams.webidl

@@ -9,6 +9,7 @@
 [Exposed=(Window,Worker)]
 interface URLSearchParams {
   [Throws] constructor(optional (sequence<sequence<USVString>> or record<USVString, USVString> or USVString) init = "");
+  readonly attribute unsigned long size;
   undefined append(USVString name, USVString value);
   undefined delete(USVString name);
   USVString? get(USVString name);

tests/wpt/metadata/url/urlsearchparams-size.any.js.ini

@@ -1,26 +0,0 @@
-[urlsearchparams-size.any.html]
-  [URLSearchParams's size and deletion]
-    expected: FAIL
-
-  [URLSearchParams's size and addition]
-    expected: FAIL
-
-  [URLSearchParams's size when obtained from a URL]
-    expected: FAIL
-
-  [URLSearchParams's size when obtained from a URL and using .search]
-    expected: FAIL
-
-
-[urlsearchparams-size.any.worker.html]
-  [URLSearchParams's size and deletion]
-    expected: FAIL
-
-  [URLSearchParams's size and addition]
-    expected: FAIL
-
-  [URLSearchParams's size when obtained from a URL]
-    expected: FAIL
-
-  [URLSearchParams's size when obtained from a URL and using .search]
-    expected: FAIL