[SVGDom] Linear gradient 'gradientTransform' support

experimental/svg/model/SkSVGLinearGradient.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 SkSVGLinearGradient_DEFINED
 #define SkSVGLinearGradient_DEFINED
 
 #include "SkSVGHiddenContainer.h"
 #include "SkSVGTypes.h"
 
 class SkSVGLinearGradient : public SkSVGHiddenContainer {
 public:
     virtual ~SkSVGLinearGradient() = default;
     static sk_sp<SkSVGLinearGradient> Make() {
         return sk_sp<SkSVGLinearGradient>(new SkSVGLinearGradient());
     }
 
     void setHref(const SkSVGStringType&);
+    void setGradientTransform(const SkSVGTransformType&);
     void setSpreadMethod(const SkSVGSpreadMethod&);
     void setX1(const SkSVGLength&);
     void setY1(const SkSVGLength&);
     void setX2(const SkSVGLength&);
     void setY2(const SkSVGLength&);
 
 protected:
     bool onAsPaint(const SkSVGRenderContext&, SkPaint*) const override;
 
     void onSetAttribute(SkSVGAttribute, const SkSVGValue&) override;
 
 private:
     SkSVGLinearGradient();
 
     void collectColorStops(const SkSVGRenderContext&,
                            SkSTArray<2, SkScalar, true>*,
                            SkSTArray<2, SkColor, true>*) const;
 
     SkSVGLength fX1 = SkSVGLength(0  , SkSVGLength::Unit::kPercentage);
     SkSVGLength fY1 = SkSVGLength(0  , SkSVGLength::Unit::kPercentage);
     SkSVGLength fX2 = SkSVGLength(100, SkSVGLength::Unit::kPercentage);
     SkSVGLength fY2 = SkSVGLength(0  , SkSVGLength::Unit::kPercentage);
 
-    SkSVGStringType   fHref;
-    SkSVGSpreadMethod fSpreadMethod = SkSVGSpreadMethod(SkSVGSpreadMethod::Type::kPad);
+    SkSVGStringType    fHref;
+    SkSVGTransformType fGradientTransform = SkSVGTransformType(SkMatrix::I());
+    SkSVGSpreadMethod  fSpreadMethod = SkSVGSpreadMethod(SkSVGSpreadMethod::Type::kPad);
 
     typedef SkSVGHiddenContainer INHERITED;
 };
 
 #endif // SkSVGLinearGradient_DEFINED