Oilpan: Remove most WillBe types from the code base

third_party/WebKit/Source/core/css/cssom/PositionValue.h

 // Copyright 2016 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 PositionValue_h
 #define PositionValue_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/CoreExport.h"
 #include "core/css/cssom/LengthValue.h"
 #include "core/css/cssom/StyleValue.h"
 
 namespace blink {
 
 class CORE_EXPORT PositionValue final : public StyleValue {
     WTF_MAKE_NONCOPYABLE(PositionValue);
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PositionValue* create(const LengthValue* x, const LengthValue* y)
     {
         return new PositionValue(x, y);
     }
 
     // Bindings require a non const return value.
     LengthValue* x() const { return const_cast<LengthValue*>(m_x.get()); }
     LengthValue* y() const { return const_cast<LengthValue*>(m_y.get()); }
 
     StyleValueType type() const override { return PositionValueType; }
 
-    PassRefPtrWillBeRawPtr<CSSValue> toCSSValue() const override;
+    RawPtr<CSSValue> toCSSValue() const override;
 
     DEFINE_INLINE_VIRTUAL_TRACE()
     {
         visitor->trace(m_x);
         visitor->trace(m_y);
         StyleValue::trace(visitor);
     }
 
 protected:
     PositionValue(const LengthValue* x, const LengthValue* y) : m_x(x),
         m_y(y) {}
 
     Member<const LengthValue> m_x;
     Member<const LengthValue> m_y;
 
 };
 
 } // namespace blink
 
 #endif