Oilpan: Prepare moving InspectorAgent related classes to oilpan

Source/core/inspector/InspectorBaseAgent.h

Index: Source/core/inspector/InspectorBaseAgent.h
diff --git a/Source/core/inspector/InspectorBaseAgent.h b/Source/core/inspector/InspectorBaseAgent.h
index dfda25164bd6c4dc0c20893bfcb6407a128b2e68..76c0b11c83328fd03a856614d1317579ef245ca1 100644
--- a/Source/core/inspector/InspectorBaseAgent.h
+++ b/Source/core/inspector/InspectorBaseAgent.h
@@ -48,7 +48,7 @@ class InspectorAgent : public NoBaseWillBeGarbageCollectedFinalized<InspectorAge
 public:
     explicit InspectorAgent(const String&);
     virtual ~InspectorAgent();
-    virtual void trace(Visitor*) { }
+    virtual void trace(Visitor*);
 
     virtual void init() { }
     virtual void setFrontend(InspectorFrontend*) { }
@@ -63,7 +63,7 @@ public:
     void appended(InstrumentingAgents*, InspectorState*);
 
 protected:
-    InstrumentingAgents* m_instrumentingAgents;
+    RawPtrWillBeMember<InstrumentingAgents> m_instrumentingAgents;
     InspectorState* m_state;
 
 private:
@@ -85,7 +85,7 @@ public:
     void trace(Visitor*);
 
 private:
-    InstrumentingAgents* m_instrumentingAgents;
+    RawPtrWillBeMember<InstrumentingAgents> m_instrumentingAgents;
     InspectorCompositeState* m_inspectorState;
     WillBeHeapVector<OwnPtrWillBeMember<InspectorAgent> > m_agents;
 };