The type argument for HTMLCanvasElement toDataURL() api should not be nullable

Source/core/html/HTMLCanvasElement.idl

Index: Source/core/html/HTMLCanvasElement.idl
diff --git a/Source/core/html/HTMLCanvasElement.idl b/Source/core/html/HTMLCanvasElement.idl
index b6d326c40df78aff6e2585d905f6867b69643a5c..a16f591356d480ba887e0f8606cf9ecd45340eac 100644
--- a/Source/core/html/HTMLCanvasElement.idl
+++ b/Source/core/html/HTMLCanvasElement.idl
@@ -49,6 +49,5 @@ interface HTMLCanvasElement : HTMLElement {
 
     // Note: The arguments argument is variadic in the spec, but not here as
     // only one extra argument is actually used.
-    // FIXME: type should not be nullable or have a default value.

[philipj_slow, 2015/07/23 08:02:12]

It still has a default value null, so leave that part of the FIXME. Actually
fixing that has the same problem as in
https://codereview.chromium.org/1225813003/ and I think you'll find this again
and again.

[shiva.jm, 2015/07/23 08:33:40]

Done.

-    [RaisesException] DOMString toDataURL(optional DOMString? type = null, optional any arguments);
+    [RaisesException] DOMString toDataURL(optional DOMString type = null, optional any arguments);
 };