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 935f204d0b15cd1b3c02c9ef84baf237c8c6f22f..0897424d9eb28d04538abd2fff81044d14a97af2 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.h
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.h
@@ -34,6 +34,7 @@
 #include "core/platform/graphics/GraphicsTypes.h"
 #include "core/platform/graphics/ImageBuffer.h"
 #include "core/platform/graphics/Path.h"
+#include "core/svg/SVGMatrix.h"
 #include "platform/geometry/FloatSize.h"
 #include "platform/transforms/AffineTransform.h"
 #include "wtf/HashMap.h"
@@ -117,6 +118,12 @@ 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);