Implement canvas focus ring methods.

Source/core/html/canvas/CanvasRenderingContext2D.idl

Index: Source/core/html/canvas/CanvasRenderingContext2D.idl
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.idl b/Source/core/html/canvas/CanvasRenderingContext2D.idl
index ed6cbc44aab2df55d18300d6320f9e690c8f9d6c..de8f522a73fe7ecab68ffc31ac4220e15903b67c 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.idl
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.idl
@@ -159,6 +159,12 @@ interface CanvasRenderingContext2D : CanvasRenderingContext {
 
     [RaisesException] ImageData webkitGetImageDataHD(float sx, float sy, float sw, float sh);
 
+    // Focus rings
+    void drawSystemFocusRing(Element element);
+    void drawSystemFocusRing(Path path, Element element);
+    boolean drawCustomFocusRing(Element element);
+    boolean drawCustomFocusRing(Path path, Element element);
+
     readonly attribute float webkitBackingStorePixelRatio;
 
     attribute boolean webkitImageSmoothingEnabled;