Implement the infrastructure of creating WorkerFetchContext in worker global scope.

third_party/WebKit/Source/platform/loader/fetch/FetchContext.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 24 matching lines @@
 #include "platform/heap/Handle.h"
 #include "platform/loader/fetch/FetchInitiatorInfo.h"
 #include "platform/loader/fetch/FetchParameters.h"
 #include "platform/loader/fetch/Resource.h"
 #include "platform/loader/fetch/ResourceLoadPriority.h"
 #include "platform/loader/fetch/ResourceRequest.h"
 #include "platform/network/ContentSecurityPolicyParsers.h"
 #include "platform/weborigin/SecurityViolationReportingPolicy.h"
 #include "platform/wtf/Forward.h"
 #include "platform/wtf/Noncopyable.h"
+#include "public/platform/WebURLLoader.h"
 
 namespace blink {
 
 class ClientHintsPreferences;
 class KURL;
 class MHTMLArchive;
 class PlatformProbeSink;
 class ResourceError;
 class ResourceResponse;
 class ResourceTimingInfo;
@@ skipping 152 matching lines @@
       ResourceLoadPriority priority) {
     return priority;
   }
 
   virtual RefPtr<WebTaskRunner> LoadingTaskRunner() const { return nullptr; }
 
   PlatformProbeSink* GetPlatformProbeSink() const {
     return platform_probe_sink_;
   }
 
+  virtual std::unique_ptr<WebURLLoader> CreateURLLoader() { return nullptr; }
+
  protected:
   FetchContext();
 
  private:
   Member<PlatformProbeSink> platform_probe_sink_;
 };
 
 }  // namespace blink
 
 #endif