[SVGDom/experimental] Initial SVGLength support

experimental/svg/model/SkSVGValue.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkSVGValue_DEFINED
 #define SkSVGValue_DEFINED
 
 #include "SkColor.h"
 #include "SkMatrix.h"
 #include "SkPath.h"
+#include "SkSVGTypes.h"
 #include "SkTypes.h"
 
 class SkSVGValue : public SkNoncopyable {
 public:
     enum class Type {
-        Color,
-        Path,
-        Transform,
+        kColor,
+        kLength,
+        kPath,
+        kTransform,
     };
 
     Type type() const { return fType; }
 
     template <typename T>
     const T* as() const {
         return fType == T::TYPE ? static_cast<const T*>(this) : nullptr;
     }
 
 protected:
     SkSVGValue(Type t) : fType(t) { }
 
 private:
     Type fType;
+
+    typedef SkNoncopyable INHERITED;
 };
 
 template <typename SkiaType, SkSVGValue::Type ValueType>
 class SkSVGWrapperValue final : public SkSVGValue {
 public:
     static constexpr Type TYPE = ValueType;
 
     explicit SkSVGWrapperValue(const SkiaType& v)
         : INHERITED(ValueType)
         , fWrappedValue(v) { }
 
     operator const SkiaType&() const { return fWrappedValue; }
 
 private:
     SkiaType fWrappedValue;
 
-    using INHERITED = SkSVGValue;
+    typedef SkSVGValue INHERITED;
 };
 
-using SkSVGColorValue     = SkSVGWrapperValue<SkColor , SkSVGValue::Type::Color    >;
-using SkSVGPathValue      = SkSVGWrapperValue<SkPath  , SkSVGValue::Type::Path     >;
-using SkSVGTransformValue = SkSVGWrapperValue<SkMatrix, SkSVGValue::Type::Transform>;
+using SkSVGColorValue     = SkSVGWrapperValue<SkSVGColor , SkSVGValue::Type::kColor    >;
+using SkSVGLengthValue    = SkSVGWrapperValue<SkSVGLength, SkSVGValue::Type::kLength   >;
+using SkSVGPathValue      = SkSVGWrapperValue<SkPath     , SkSVGValue::Type::kPath     >;
+using SkSVGTransformValue = SkSVGWrapperValue<SkMatrix   , SkSVGValue::Type::kTransform>;
 
 #endif // SkSVGValue_DEFINED