Oilpan: Fix compile after r200678.

Source/core/inspector/InspectorDebuggerAgent.h

 /*
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010-2011 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 24 matching lines @@
 #include "core/inspector/V8DebuggerAgent.h"
 
 namespace blink {
 
 class CORE_EXPORT InspectorDebuggerAgent
     : public InspectorBaseAgent<InspectorDebuggerAgent, InspectorFrontend::Debugger>
     , public InspectorBackendDispatcher::DebuggerCommandHandler
     , public V8DebuggerAgent::Client {
 public:
     ~InspectorDebuggerAgent() override;
+    DECLARE_VIRTUAL_TRACE();
 
     // InspectorBackendDispatcher::DebuggerCommandHandler implementation.
     void enable(ErrorString*) override;
     void disable(ErrorString*) override;
     void setBreakpointsActive(ErrorString*, bool inActive) override;
     void setSkipAllPauses(ErrorString*, bool inSkipped) override;
     void setBreakpointByUrl(ErrorString*, int inLineNumber, const String* inUrl, const String* inUrlRegex, const int* inColumnNumber, const String* inCondition, TypeBuilder::Debugger::BreakpointId* outBreakpointId, RefPtr<TypeBuilder::Array<TypeBuilder::Debugger::Location>>& outLocations) override;
     void setBreakpoint(ErrorString*, const RefPtr<JSONObject>& inLocation, const String* inCondition, TypeBuilder::Debugger::BreakpointId* outBreakpointId, RefPtr<TypeBuilder::Debugger::Location>& outActualLocation) override;
     void removeBreakpoint(ErrorString*, const String& inBreakpointId) override;
     void continueToLocation(ErrorString*, const RefPtr<JSONObject>& inLocation, const bool* inInterstatementLocation) override;
@@ skipping 46 matching lines @@
     void init() override;
     void setFrontend(InspectorFrontend*) override;
     void clearFrontend() override;
     void restore() override;
 
     V8DebuggerAgent* v8DebuggerAgent() const { return m_v8DebuggerAgent.get(); }
 
 protected:
     InspectorDebuggerAgent(InjectedScriptManager*, V8Debugger*, int contextGroupId);
 
-    OwnPtr<V8DebuggerAgent> m_v8DebuggerAgent;
+    OwnPtrWillBeMember<V8DebuggerAgent> m_v8DebuggerAgent;
 };
 
 } // namespace blink
 
 
 #endif // !defined(InspectorDebuggerAgent_h)