Oilpan: make SuspendableScriptExecutor safe.

Source/web/SuspendableScriptExecutor.h

Index: Source/web/SuspendableScriptExecutor.h
diff --git a/Source/web/SuspendableScriptExecutor.h b/Source/web/SuspendableScriptExecutor.h
index 476202050555924fba8a1ae72c6f50cb71c5b670..331e003b1d1b9b8f4ad8edce357031bf8267068b 100644
--- a/Source/web/SuspendableScriptExecutor.h
+++ b/Source/web/SuspendableScriptExecutor.h
@@ -16,7 +16,7 @@ class LocalFrame;
 class ScriptSourceCode;
 class WebScriptExecutionCallback;
 
-class SuspendableScriptExecutor final : public RefCountedWillBeRefCountedGarbageCollected<SuspendableScriptExecutor>, public SuspendableTimer {
+class SuspendableScriptExecutor final : public RefCountedWillBeGarbageCollectedFinalized<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*);
@@ -24,6 +24,9 @@ public:
 
     virtual void contextDestroyed() override;
 
+    // Eager finalization is needed to promptly stop this timer object.
+    // (see DOMTimer comment for more.)
+    EAGERLY_FINALIZE();
     DECLARE_VIRTUAL_TRACE();
 
 private:
@@ -33,6 +36,7 @@ private:
 
     void run();
     void executeAndDestroySelf();
+    void dispose();
 
     RawPtrWillBeMember<LocalFrame> m_frame;
     int m_worldID;