Remove BarProp.visible TODO that has been fixed in the spec

NOTRY=true
R=fs@opera.com

Review URL: https://codereview.chromium.org/1328723004

git-svn-id: svn://svn.chromium.org/blink/trunk@201721 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/frame/BarProp.idl

@@ -31,7 +31,5 @@
 [
     WillBeGarbageCollected,
 ] interface BarProp {
-    // TODO(philipj): Remove readonly or have it added to the spec:
-    // https://www.w3.org/Bugs/Public/show_bug.cgi?id=28697
     readonly attribute boolean visible;
 };