Remove PreFinalizer{Callback} type aliases from view.

third_party/WebKit/Source/platform/heap/ThreadState.h

Index: third_party/WebKit/Source/platform/heap/ThreadState.h
diff --git a/third_party/WebKit/Source/platform/heap/ThreadState.h b/third_party/WebKit/Source/platform/heap/ThreadState.h
index 5c387fed8bb1c811caf8179ef2243dd433106ac4..a8c771b8db65a1b8b443db26b52c31adad5d5228 100644
--- a/third_party/WebKit/Source/platform/heap/ThreadState.h
+++ b/third_party/WebKit/Source/platform/heap/ThreadState.h
@@ -117,8 +117,6 @@ class PLATFORM_EXPORT ThreadState {
   WTF_MAKE_NONCOPYABLE(ThreadState);
 
  public:
-  typedef std::pair<void*, PreFinalizerCallback> PreFinalizer;
-
   // See setGCState() for possible state transitions.
   enum GCState {
     NoGCScheduled,
@@ -705,6 +703,9 @@ class PLATFORM_EXPORT ThreadState {
 
   std::unique_ptr<CallbackStack> m_threadLocalWeakCallbackStack;
 
+  using PreFinalizerCallback = bool (*)(void*);
+  using PreFinalizer = std::pair<void*, PreFinalizerCallback>;
+
   // Pre-finalizers are called in the reverse order in which they are
   // registered by the constructors (including constructors of Mixin objects)
   // for an object, by processing the m_orderedPreFinalizers back-to-front.