Use Length for the stroke-dasharray property in SVGLayoutStyle

Source/wtf/RefVector.h

 // 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.
 
 #ifndef RefVector_h
 #define RefVector_h
 
 #include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 template <typename T>
 class RefVector : public RefCounted<RefVector<T>> {
 public:
     static PassRefPtr<RefVector> create() { return adoptRef(new RefVector<T>); }
     PassRefPtr<RefVector> copy() { return adoptRef(new RefVector<T>(*this)); }
 
     const T& operator[](size_t i) const { return m_vector[i]; }
     T& operator[](size_t i) { return m_vector[i]; }
     const T& at(size_t i) const { return m_vector.at(i); }
     T& at(size_t i) { return m_vector.at(i); }
 
     bool operator==(const RefVector& o) const { return m_vector == o.m_vector; }
     bool operator!=(const RefVector& o) const { return m_vector != o.m_vector; }
 
     size_t size() const { return m_vector.size(); }
+    bool isEmpty() const { return !size(); }
     void append(const T& decoration) { m_vector.append(decoration); }
     const Vector<T>& vector() const { return m_vector; }
 
 private:
     Vector<T> m_vector;
     RefVector() { }
     RefVector(const RefVector& o) : m_vector(o.m_vector) { }
 };
 
 } // namespace blink
 
 #endif // RefVector_h