Use LocalFrame::client() than getting the FrameLoader and then call client() on it.

third_party/WebKit/Source/core/loader/FrameFetchContext.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 28 matching lines @@
 #include "core/loader/LinkLoader.h"
 #include "platform/heap/Handle.h"
 #include "platform/network/ResourceRequest.h"
 #include "wtf/Forward.h"
 
 namespace blink {
 
 class ClientHintsPreferences;
 class Document;
 class DocumentLoader;
+class FrameLoaderClient;
 class LocalFrame;
 class ResourceError;
 class ResourceResponse;
 
 class CORE_EXPORT FrameFetchContext final : public FetchContext {
  public:
   static ResourceFetcher* createFetcherFromDocumentLoader(
       DocumentLoader* loader) {
     return ResourceFetcher::create(new FrameFetchContext(loader, nullptr));
   }
@@ skipping 109 matching lines @@
   RefPtr<WebTaskRunner> loadingTaskRunner() const override;
 
   DECLARE_VIRTUAL_TRACE();
 
  private:
   FrameFetchContext(DocumentLoader*, Document*);
   inline DocumentLoader* masterDocumentLoader() const;
 
   LocalFrame* frameOfImportsController() const;
   LocalFrame* frame() const;
+
+  FrameLoaderClient* frameLoaderClient() const;
+
   void printAccessDeniedMessage(const KURL&) const;
   ResourceRequestBlockedReason canRequestInternal(
       Resource::Type,
       const ResourceRequest&,
       const KURL&,
       const ResourceLoaderOptions&,
       bool forPreload,
       FetchRequest::OriginRestriction,
       ResourceRequest::RedirectStatus) const;
 
@@ skipping 11 matching lines @@
   // FIXME: Oilpan: Ideally this should just be a traced Member but that will
   // currently leak because ComputedStyle and its data are not on the heap.
   // See crbug.com/383860 for details.
   WeakMember<Document> m_document;
   Member<DocumentLoader> m_documentLoader;
 };
 
 }  // namespace blink
 
 #endif