Improve DEFINE_STATIC_LOCAL()'s handling of Blink GCed objects.

third_party/WebKit/Source/core/css/CSSPathValue.cpp

 // Copyright 2014 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.
 
 #include "core/css/CSSPathValue.h"
 
 #include "core/style/StylePath.h"
 #include "core/svg/SVGPathUtilities.h"
 
 namespace blink {
@@ skipping 21 matching lines @@
 {
     OwnPtr<SVGPathByteStream> pathByteStream = SVGPathByteStream::create();
     // Need to be registered as LSan ignored, as it will be reachable and
     // separately referred to by emptyPathValue() callers.
     LEAK_SANITIZER_IGNORE_OBJECT(pathByteStream.get());
     return CSSPathValue::create(pathByteStream.release());
 }
 
 } // namespace
 
-CSSPathValue* CSSPathValue::emptyPathValue()
+CSSPathValue& CSSPathValue::emptyPathValue()
 {
-    DEFINE_STATIC_LOCAL(Persistent<CSSPathValue>, empty, (createPathValue()));
-    return empty.get();
+    DEFINE_STATIC_LOCAL(CSSPathValue, empty, (createPathValue()));
+    return empty;
 }
 
 String CSSPathValue::customCSSText() const
 {
     return "path('" + buildStringFromByteStream(byteStream()) + "')";
 }
 
 bool CSSPathValue::equals(const CSSPathValue& other) const
 {
     return byteStream() == other.byteStream();
 }
 
 DEFINE_TRACE_AFTER_DISPATCH(CSSPathValue)
 {
     CSSValue::traceAfterDispatch(visitor);
 }
 
 } // namespace blink