Support currentTransform in 2D Canvas.

Source/core/html/canvas/CanvasRenderingContext2D.cpp

Index: Source/core/html/canvas/CanvasRenderingContext2D.cpp
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.cpp b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
index 3225ecd6344fed465e421df94628b5dea72dc844..d1c3e5990757b1842567f1185aae59a994f2093e 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.cpp
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
@@ -64,6 +64,7 @@
 #include "core/platform/graphics/transforms/AffineTransform.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderTheme.h"
+#include "core/svg/SVGMatrix.h"
 #include "weborigin/SecurityOrigin.h"
 #include "wtf/CheckedArithmetic.h"
 #include "wtf/MathExtras.h"
@@ -596,6 +597,16 @@ void CanvasRenderingContext2D::setGlobalCompositeOperation(const String& operati
     c->setCompositeOperation(op, blendMode);
 }
 
+SVGMatrix CanvasRenderingContext2D::currentTransform() const
+{
+    return SVGMatrix(state().m_transform);
+}
+
+void CanvasRenderingContext2D::setCurrentTransform(const SVGMatrix& currentTransform)
+{
+    setTransform(currentTransform.a(), currentTransform.b(), currentTransform.c(), currentTransform.d(), currentTransform.e(), currentTransform.f());
+}
+
 void CanvasRenderingContext2D::scale(float sx, float sy)
 {
     GraphicsContext* c = drawingContext();
@@ -698,12 +709,12 @@ void CanvasRenderingContext2D::transform(float m11, float m12, float m21, float
 
     realizeSaves();
 
+    modifiableState().m_transform = newTransform;
     if (!newTransform.isInvertible()) {
         modifiableState().m_invertibleCTM = false;
         return;
     }
 
-    modifiableState().m_transform = newTransform;
     c->concatCTM(transform);
     m_path.transform(transform.inverse());
 }