Remove PluginLoadObserver and related logic, it was only used for NPAPI.

third_party/WebKit/Source/web/WebDataSourceImpl.h

 /*
  * Copyright (C) 2009 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 19 matching lines @@
 
 #ifndef WebDataSourceImpl_h
 #define WebDataSourceImpl_h
 
 #include "core/loader/DocumentLoader.h"
 #include "platform/exported/WrappedResourceRequest.h"
 #include "platform/exported/WrappedResourceResponse.h"
 #include "platform/heap/Handle.h"
 #include "platform/weborigin/KURL.h"
 #include "public/web/WebDataSource.h"
-#include "web/WebPluginLoadObserver.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 class WebDataSourceImpl final : public DocumentLoader, public WebDataSource {
 public:
     static PassRefPtrWillBeRawPtr<WebDataSourceImpl> create(LocalFrame*, const ResourceRequest&, const SubstituteData&);
 
@@ skipping 12 matching lines @@
     void redirectChain(WebVector<WebURL>&) const override;
     bool isClientRedirect() const override;
     bool replacesCurrentHistoryItem() const override;
     WebNavigationType navigationType() const override;
     ExtraData* extraData() const override;
     void setExtraData(ExtraData*) override;
     void setNavigationStartTime(double) override;
 
     static WebNavigationType toWebNavigationType(NavigationType);
 
-    PassOwnPtrWillBeRawPtr<WebPluginLoadObserver> releasePluginLoadObserver() { return m_pluginLoadObserver.release(); }
-    static void setNextPluginLoadObserver(PassOwnPtrWillBeRawPtr<WebPluginLoadObserver>);
-
     DECLARE_VIRTUAL_TRACE();
 
 private:
     WebDataSourceImpl(LocalFrame*, const ResourceRequest&, const SubstituteData&);
     ~WebDataSourceImpl() override;
     void detachFromFrame() override;
     String debugName() const override { return "WebDataSourceImpl"; }
 
     // Mutable because the const getters will magically sync these to the
     // latest version from WebKit.
     mutable WrappedResourceRequest m_originalRequestWrapper;
     mutable WrappedResourceRequest m_requestWrapper;
     mutable WrappedResourceResponse m_responseWrapper;
 
     OwnPtr<ExtraData> m_extraData;
-    OwnPtrWillBeMember<WebPluginLoadObserver> m_pluginLoadObserver;
 };
 
 } // namespace blink
 
 #endif  // WebDataSourceImpl_h