Canvas focus outline should match style in html.css.

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 8d05fc093e8cd40d5091feb371b3d20212aa60e1..e9c2d9501c1e40a6e2be35657a4b2e8c5faf9d94 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.h
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.h
@@ -327,7 +327,7 @@ private:
 
     bool focusRingCallIsValid(const Path&, Element*);
     void updateFocusRingAccessibility(const Path&, Element*);
-    void drawFocusRing(const Path&, Element*);
+    void drawFocusRing(const Path&);
 
     virtual bool is2d() const OVERRIDE { return true; }
     virtual bool isAccelerated() const OVERRIDE;