Oilpan: Remove most WillBe types from the code base

third_party/WebKit/Source/core/html/shadow/DateTimeFieldElement.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 31 matching lines @@
     WTF_MAKE_NONCOPYABLE(DateTimeFieldElement);
 
 public:
     enum EventBehavior {
         DispatchNoEvent,
         DispatchEvent,
     };
 
     // FieldOwner implementer must call removeEventHandler when
     // it doesn't handle event, e.g. at destruction.
-    class FieldOwner : public WillBeGarbageCollectedMixin {
+    class FieldOwner : public GarbageCollectedMixin {
     public:
         virtual ~FieldOwner();
         virtual void didBlurFromField() = 0;
         virtual void didFocusOnField() = 0;
         virtual void fieldValueChanged() = 0;
         virtual bool focusOnNextField(const DateTimeFieldElement&) = 0;
         virtual bool focusOnPreviousField(const DateTimeFieldElement&) = 0;
         virtual bool isFieldOwnerDisabled() const = 0;
         virtual bool isFieldOwnerReadOnly() const = 0;
         virtual AtomicString localeIdentifier() const = 0;
@@ skipping 33 matching lines @@
     // Node functions.
     void setFocus(bool) override;
 
 private:
     void defaultKeyboardEventHandler(KeyboardEvent*);
     bool isDateTimeFieldElement() const final;
     bool isFieldOwnerDisabled() const;
     bool isFieldOwnerReadOnly() const;
     bool supportsFocus() const final;
 
-    RawPtrWillBeMember<FieldOwner> m_fieldOwner;
+    Member<FieldOwner> m_fieldOwner;
 };
 
 } // namespace blink
 
 #endif
 #endif