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 34 matching lines @@
 namespace blink {
 
 class ClientHintsPreferences;
 class KURL;
 class MHTMLArchive;
 class PlatformProbeSink;
 class ResourceError;
 class ResourceResponse;
 class ResourceTimingInfo;
 class WebTaskRunner;
+class WebURLLoader;
 enum class WebCachePolicy;
 
 enum FetchResourceType { kFetchMainResource, kFetchSubresource };
 
 // The FetchContext is an interface for performing context specific processing
 // in response to events in the ResourceFetcher. The ResourceFetcher or its job
 // class, ResourceLoader, may call the methods on a FetchContext.
 //
 // Any processing that depends on components outside platform/loader/fetch/
 // should be implemented on a subclass of this interface, and then exposed to
@@ skipping 129 matching lines @@
       ResourceLoadPriority priority) {
     return priority;
   }
 
   virtual RefPtr<WebTaskRunner> LoadingTaskRunner() const { return nullptr; }
 
   PlatformProbeSink* GetPlatformProbeSink() const {
     return platform_probe_sink_;
   }
 
+  virtual WebURLLoader* CreateURLLoader() { return nullptr; }
+
  protected:
   FetchContext();
 
  private:
   Member<PlatformProbeSink> platform_probe_sink_;
 };
 
 }  // namespace blink
 
 #endif