Throw when failing to convert sequence inner values

Cargo.lock

@@ -3097,7 +3097,7 @@ dependencies = [
 [[package]]
 name = "mozjs"
 version = "0.12.1"
-source = "git+https://github.com/servo/rust-mozjs#0832eb778689143cd9f2f3967fac912f7096a466"
+source = "git+https://github.com/servo/rust-mozjs#c2896b9c9f8681070890bc9582378472d0139b13"
 dependencies = [
  "cc",
  "lazy_static",

tests/wpt/metadata/MANIFEST.json

@@ -461344,7 +461344,7 @@
    "testharness"
   ],
   "WebIDL/ecmascript-binding/sequence-conversion.html": [
-   "4caa5563b56b55ffb01a81e63c69ac0f009bda77",
+   "f878a2672e3082c4f617bbb314cf2de84266f729",
    "testharness"
   ],
   "WebIDL/ecmascript-binding/support/constructors-support.html": [

tests/wpt/web-platform-tests/WebIDL/ecmascript-binding/sequence-conversion.html

@@ -128,4 +128,9 @@ test(t => {
   assert_array_equals(ctx.getLineDash(), [13, 14, 15, 16]);
 }, "A holey array with fallback to an accessor on the prototype");
 
+test(t => {
+  // Should fail rather than falling back to record
+  assert_throws(new TypeError(), function() { new URLSearchParams(["key", "value"]); });
+}, "A string array in sequence<sequence> or record");
+
 </script>