Oilpan: tidy up some inter-stack object references.

Source/core/css/parser/CSSSupportsParser.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 CSSSupportsParser_h
 #define CSSSupportsParser_h
 
+#include "platform/heap/Handle.h"
+
 namespace blink {
 
 class CSSParserImpl;
 class CSSParserTokenRange;
 
 class CSSSupportsParser {
+    STACK_ALLOCATED();
 public:
     enum SupportsResult {
         Unsupported = false,
         Supported = true,
         Invalid
     };
 
     static SupportsResult supportsCondition(CSSParserTokenRange, CSSParserImpl&);
 
 private:
     CSSSupportsParser(CSSParserImpl& parser) : m_parser(parser) { }
 
     SupportsResult consumeCondition(CSSParserTokenRange);
     SupportsResult consumeNegation(CSSParserTokenRange);
 
     SupportsResult consumeConditionInParenthesis(CSSParserTokenRange&);
 
     CSSParserImpl& m_parser;
 };
 
 } // namespace blink
 
 #endif // CSSSupportsParser_h