Oilpan: Remove most WillBe types from the code base

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

 // Copyright 2015 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 NumberValue_h
 #define NumberValue_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/CoreExport.h"
 #include "core/css/CSSPrimitiveValue.h"
 #include "core/css/cssom/StyleValue.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class CORE_EXPORT NumberValue final : public StyleValue {
     WTF_MAKE_NONCOPYABLE(NumberValue);
     DEFINE_WRAPPERTYPEINFO();
 public:
     static NumberValue* create(double value)
     {
         return new NumberValue(value);
     }
 
     double value() const { return m_value; }
 
-    PassRefPtrWillBeRawPtr<CSSValue> toCSSValue() const override
+    RawPtr<CSSValue> toCSSValue() const override
     {
         return cssValuePool().createValue(m_value, CSSPrimitiveValue::UnitType::
 Number);
     }
 
     StyleValueType type() const override { return StyleValueType::NumberType; }
 private:
     NumberValue(double value) : m_value(value) {}
 
     double m_value;
 };
 
 } // namespace blink
 
 #endif