Oilpan: move context menu providers to the heap.

Source/core/inspector/InspectorFrontendHost.h

 /*
  * Copyright (C) 2007 Apple 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 57 matching lines @@
     void sendMessageToEmbedder(const String& message);
 
     String getSelectionBackgroundColor();
     String getSelectionForegroundColor();
 
     bool isUnderTest();
     bool isHostedMode();
 
     Page* frontendPage() { return m_frontendPage; }
 
+    void clearMenuProvider() { m_menuProvider = nullptr; }
+
 private:
-    friend class FrontendMenuProvider;
     InspectorFrontendHost(InspectorFrontendClient* client, Page* frontendPage);
 
     InspectorFrontendClient* m_client;
     RawPtrWillBeMember<Page> m_frontendPage;
-    FrontendMenuProvider* m_menuProvider;
+    RawPtrWillBeMember<FrontendMenuProvider> m_menuProvider;
 };
 
 } // namespace blink
 
 #endif // InspectorFrontendHost_h