Not for review - Rebase of crrev.com/62833003

Source/core/workers/UIWorker.idl

Index: Source/core/workers/UIWorker.idl
diff --git a/Source/core/workers/Worker.idl b/Source/core/workers/UIWorker.idl
similarity index 86%
copy from Source/core/workers/Worker.idl
copy to Source/core/workers/UIWorker.idl
index 1e6cd0464934ef2d5e2d5a8004ae42098f86fed4..1bf37e65b938e50491cf96291d52e767949f520a 100644
--- a/Source/core/workers/Worker.idl
+++ b/Source/core/workers/UIWorker.idl
@@ -32,12 +32,6 @@
     Constructor(DOMString scriptUrl),
     ConstructorCallWith=ExecutionContext,
     RaisesException=Constructor,
-] interface Worker : EventTarget {
-
-    attribute EventHandler onmessage;
-
-    [Custom, RaisesException] void postMessage(SerializedScriptValue message, optional sequence<Transferable> transfer);
-    void terminate();
+    WillBeGarbageCollected,
+] interface UIWorker : Worker {
 };
-
-Worker implements AbstractWorker;