The contextId argument for HTMLCanvasElement getContext() api should not be optional

LayoutTests/fast/dom/script-tests/non-numeric-values-numeric-parameters.js

Index: LayoutTests/fast/dom/script-tests/non-numeric-values-numeric-parameters.js
diff --git a/LayoutTests/fast/dom/script-tests/non-numeric-values-numeric-parameters.js b/LayoutTests/fast/dom/script-tests/non-numeric-values-numeric-parameters.js
index 5eb07bdf4325fb22ffcb8deaf9b32396ced360dc..3d125ade216823ae6125efdc6a024eec63c61523 100644
--- a/LayoutTests/fast/dom/script-tests/non-numeric-values-numeric-parameters.js
+++ b/LayoutTests/fast/dom/script-tests/non-numeric-values-numeric-parameters.js
@@ -172,6 +172,11 @@ function createHTMLTableRowElement()
     return row;
 }
 
+function createCanvasElement()
+{
+    return document.createElement("canvas");
+}
+
 // CharacterData
 
 shouldBe("nonNumericPolicy('document.createTextNode(\"a\").substringData(x, 0)')", "'any type allowed'");
@@ -255,6 +260,10 @@ shouldBe("nonNumericPolicy('createHTMLTableSectionElement().deleteRow(x)')", "'a
 shouldBe("nonNumericPolicy('document.createElement(\"textarea\").setSelectionRange(x, 0)')", "'any type allowed'");
 shouldBe("nonNumericPolicy('document.createElement(\"textarea\").setSelectionRange(0, x)')", "'any type allowed'");
 
+// HTMLCanvasElement
+
+shouldBe("nonNumericPolicy('createCanvasElement().getContext(x)')", "'any type allowed (but not omitted)'");
+
 // KeyboardEvent
 
 shouldBe("nonNumericPolicy('document.createEvent(\"KeyboardEvent\").initKeyboardEvent(\"a\", false, false, null, \"b\", x, false, false, false, false, false)')", "'any type allowed'");