Support currentTransform in 2D Canvas.

Source/core/html/canvas/CanvasRenderingContext2D.h

Index: Source/core/html/canvas/CanvasRenderingContext2D.h
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.h b/Source/core/html/canvas/CanvasRenderingContext2D.h
index 46107a2e2a63580559d3bda1e19eb487bc481769..accac1e3f1a2cddb6ff892ffa0096b6129ec5199 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.h
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.h
@@ -36,6 +36,7 @@
 #include "core/platform/graphics/ImageBuffer.h"
 #include "core/platform/graphics/Path.h"
 #include "core/platform/graphics/transforms/AffineTransform.h"
+#include "core/svg/SVGMatrix.h"
 #include "wtf/HashMap.h"
 #include "wtf/Vector.h"
 #include "wtf/text/WTFString.h"
@@ -117,6 +118,11 @@ public:
     void save() { ++m_unrealizedSaveCount; }
     void restore();
 
+    SVGMatrix currentTransform() const
+    {
+        return SVGMatrix(state().m_transform);
+    }
+    void setCurrentTransform(const SVGMatrix&);
     void scale(float sx, float sy);
     void rotate(float angleInRadians);
     void translate(float tx, float ty);