Switch SuspendableScriptExecutor over to using SelfKeepAlive<>.

Source/web/SuspendableScriptExecutor.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SuspendableScriptExecutor_h
 #define SuspendableScriptExecutor_h
 
 #include "core/frame/SuspendableTimer.h"
 #include "platform/heap/Handle.h"
-#include "wtf/OwnPtr.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 class LocalFrame;
 class ScriptSourceCode;
 class WebScriptExecutionCallback;
 
-class SuspendableScriptExecutor final : public RefCountedWillBeRefCountedGarbageCollected<SuspendableScriptExecutor>, public SuspendableTimer {
+class SuspendableScriptExecutor final : public GarbageCollectedFinalized<SuspendableScriptExecutor>, public SuspendableTimer {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(SuspendableScriptExecutor);
 public:
     static void createAndRun(LocalFrame*, int worldID, const WillBeHeapVector<ScriptSourceCode>& sources, int extensionGroup, bool userGesture, WebScriptExecutionCallback*);
     ~SuspendableScriptExecutor() override;
 
     void contextDestroyed() override;
 
-    // Eager finalization is needed to promptly stop this timer object.
-    // (see DOMTimer comment for more.)
-    EAGERLY_FINALIZE();
     DECLARE_VIRTUAL_TRACE();
 
 private:
     SuspendableScriptExecutor(LocalFrame*, int worldID, const WillBeHeapVector<ScriptSourceCode>& sources, int extensionGroup, bool userGesture, WebScriptExecutionCallback*);
 
     void fired() override;
 
     void run();
     void executeAndDestroySelf();
     void dispose();
 
     RefPtrWillBeMember<LocalFrame> m_frame;
+    WillBeHeapVector<ScriptSourceCode> m_sources;
+    WebScriptExecutionCallback* m_callback;
+
+    SelfKeepAlive<SuspendableScriptExecutor> m_keepAlive;
+
     int m_worldID;
-    WillBeHeapVector<ScriptSourceCode> m_sources;
     int m_extensionGroup;
+
     bool m_userGesture;
-    WebScriptExecutionCallback* m_callback;
-#if ENABLE(ASSERT)
-    bool m_disposed;
-#endif
 };
 
 } // namespace blink
 
 #endif // SuspendableScriptExecutor_h