Oilpan: fix build after r195134.

Source/core/inspector/PerIsolateDebuggerClient.h

Index: Source/core/inspector/PerIsolateDebuggerClient.h
diff --git a/Source/core/inspector/PerIsolateDebuggerClient.h b/Source/core/inspector/PerIsolateDebuggerClient.h
index be6982cb679c679fccf27f4c535248336f2cb70b..b9c04710394a12f6130d8f820fac07ba42cac11c 100644
--- a/Source/core/inspector/PerIsolateDebuggerClient.h
+++ b/Source/core/inspector/PerIsolateDebuggerClient.h
@@ -6,19 +6,23 @@
 #define PerIsolateDebuggerClient_h
 
 #include "bindings/core/v8/ScriptDebugServer.h"
+#include "platform/heap/Handle.h"
 
 namespace blink {
 
 class PerIsolateDebuggerClient : public ScriptDebugServer::Client {
     WTF_MAKE_NONCOPYABLE(PerIsolateDebuggerClient);
 public:
-    PerIsolateDebuggerClient(v8::Isolate*, PassOwnPtr<ScriptDebugServer>);
+    PerIsolateDebuggerClient(v8::Isolate*, PassOwnPtrWillBeRawPtr<ScriptDebugServer>);
     ~PerIsolateDebuggerClient() override;
     v8::Local<v8::Object> compileDebuggerScript() override;
     ScriptDebugServer* scriptDebugServer() const { return m_scriptDebugServer.get(); }
+
+    DECLARE_VIRTUAL_TRACE();
+
 private:
     v8::Isolate* m_isolate;
-    OwnPtr<ScriptDebugServer> m_scriptDebugServer;
+    OwnPtrWillBeMember<ScriptDebugServer> m_scriptDebugServer;
 };
 
 } // namespace blink