Oilpan: prefer eager finalization over prefinalizers.

Source/platform/speech/PlatformSpeechSynthesizer.h

Index: Source/platform/speech/PlatformSpeechSynthesizer.h
diff --git a/Source/platform/speech/PlatformSpeechSynthesizer.h b/Source/platform/speech/PlatformSpeechSynthesizer.h
index f808750fe3102bb50409dfa7fcb5bda64ac19400..c54e2f1849b92a6fe28c03e3c3f62be8b558b1c7 100644
--- a/Source/platform/speech/PlatformSpeechSynthesizer.h
+++ b/Source/platform/speech/PlatformSpeechSynthesizer.h
@@ -58,12 +58,10 @@ protected:
 
 class PLATFORM_EXPORT PlatformSpeechSynthesizer : public GarbageCollectedFinalized<PlatformSpeechSynthesizer> {
     WTF_MAKE_NONCOPYABLE(PlatformSpeechSynthesizer);
-    USING_PRE_FINALIZER(PlatformSpeechSynthesizer, dispose);
 public:
     static PlatformSpeechSynthesizer* create(PlatformSpeechSynthesizerClient*);
 
     virtual ~PlatformSpeechSynthesizer();
-    void dispose();
 
     const HeapVector<Member<PlatformSpeechSynthesisVoice>>& voiceList() const { return m_voiceList; }
     virtual void speak(PlatformSpeechSynthesisUtterance*);
@@ -75,6 +73,15 @@ public:
 
     void setVoiceList(HeapVector<Member<PlatformSpeechSynthesisVoice>>&);
 
+    // Eager finalization is required to promptly release the owned WebSpeechSynthesizer.
+    //
+    // If not and delayed until lazily swept, m_webSpeechSynthesizerClient may end up
+    // being lazily swept first (i.e., before this PlatformSpeechSynthesizer), leaving
+    // m_webSpeechSynthesizer with a dangling pointer to a finalized object --
+    // WebSpeechSynthesizer embedder implementations calling notification methods in the
+    // other directions by way of m_webSpeechSynthesizerClient. Eagerly releasing
+    // WebSpeechSynthesizer prevents such unsafe accesses.
+    EAGERLY_FINALIZE();
     DECLARE_VIRTUAL_TRACE();
 
 protected: