Worklet: Introduce "pending tasks struct" concept defined in the Worklet spec

third_party/WebKit/Source/core/workers/MainThreadWorklet.h

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MainThreadWorklet_h
 #define MainThreadWorklet_h
 
 #include "core/workers/Worklet.h"
 
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/CoreExport.h"
-#include "core/workers/WorkletObjectProxy.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class LocalFrame;
 
 // A MainThreadWorklet is a worklet that runs only on the main thread.
 // TODO(nhiroki): This is a temporary class to support module loading for main
 // thread worklets. This and ThreadedWorklet will be merged into the base
 // Worklet class once threaded worklets are ready to use module loading.
-class CORE_EXPORT MainThreadWorklet : public Worklet,
-                                      public WorkletObjectProxy {
+class CORE_EXPORT MainThreadWorklet : public Worklet {
   USING_GARBAGE_COLLECTED_MIXIN(MainThreadWorklet);
   WTF_MAKE_NONCOPYABLE(MainThreadWorklet);
 
  public:
   virtual ~MainThreadWorklet() = default;
 
   // Worklet
-  ScriptPromise addModule(ScriptState*, const String& url) final;
+  ScriptPromise addModule(ScriptState*, const String& module_url) final;
 
   // ContextLifecycleObserver
   void ContextDestroyed(ExecutionContext*) final;
 
-  // WorkletObjectProxy
-  void DidFetchAndInvokeScript(int32_t request_id, bool success) final;
-
   DECLARE_VIRTUAL_TRACE();
 
  protected:
   explicit MainThreadWorklet(LocalFrame*);
-
- private:
-  HeapHashMap<int32_t /* request_id */, Member<ScriptPromiseResolver>>
-      resolver_map_;
 };
 
 }  // namespace blink
 
 #endif  // MainThreadWorklet_h