Implement URLSearchParams.

Source/core/dom/URLSearchParams.idl

Index: Source/core/dom/URLSearchParams.idl
diff --git a/Source/modules/performance/SharedWorkerPerformance.idl b/Source/core/dom/URLSearchParams.idl
similarity index 70%
copy from Source/modules/performance/SharedWorkerPerformance.idl
copy to Source/core/dom/URLSearchParams.idl
index ef8b36b7ab02a2031941fa78f1c810a734b3951b..6c31931a3f632521a925b22945c1aaea58a2219f 100644
--- a/Source/modules/performance/SharedWorkerPerformance.idl
+++ b/Source/core/dom/URLSearchParams.idl
@@ -28,8 +28,17 @@
  */
 
 [
-    RuntimeEnabled=HighResolutionTimeInWorkers,
-] partial interface SharedWorker {
-    // See https://dvcs.w3.org/hg/webperf/raw-file/tip/specs/HighResolutionTime2/Overview.html for details.
-    [CallWith=ExecutionContext] readonly attribute double workerStart;
+    Constructor(),
+    Constructor(DOMString queryString),
+    Constructor(URLSearchParams initial),
+    ImplementedAs=DOMURLSearchParams
+] interface URLSearchParams {
+    [NotEnumerable] DOMString toString();
+
+    [ImplementedAs=appendNameValue] void append(DOMString name, DOMString value);
+    [ImplementedAs=deleteAllWithName]void delete(DOMString name);
+    [ImplementedAs=getFirstValue, TreatReturnedNullStringAs=Null] DOMString get(DOMString name);
+    [ImplementedAs=getAllValues] sequence<DOMString> getAll(DOMString name);
+    [ImplementedAs=hasName] boolean has(DOMString name);
+    [ImplementedAs=setNameValue]void set(DOMString name, DOMString value);
 };