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

third_party/WebKit/Source/core/loader/WorkletScriptLoader.h

Index: third_party/WebKit/Source/core/loader/WorkletScriptLoader.h
diff --git a/third_party/WebKit/Source/core/loader/WorkletScriptLoader.h b/third_party/WebKit/Source/core/loader/WorkletScriptLoader.h
index 4785e7e7f12ea4e892a9028276426cb8fbdc0efb..633896f35b343536dc594786849fc9beedcb2d43 100644
--- a/third_party/WebKit/Source/core/loader/WorkletScriptLoader.h
+++ b/third_party/WebKit/Source/core/loader/WorkletScriptLoader.h
@@ -54,9 +54,6 @@ class WorkletScriptLoader final
   // after Client::notifyWorkletScriptLoadingFinished() is called.
   bool WasScriptLoadSuccessful() const;
 
-  void set_request_id(int32_t request_id) { request_id_ = request_id; }
-  int32_t request_id() const { return request_id_; }
-
   DECLARE_TRACE();
 
  private:
@@ -69,10 +66,6 @@ class WorkletScriptLoader final
   Member<ResourceFetcher> fetcher_;
   Member<Client> client_;
 
-  // The client of this loader can freely use this field to identify a fetch
-  // request.
-  int32_t request_id_ = -1;
-
   bool was_script_load_successful_ = false;
   bool was_script_load_complete_ = false;
 };