Make item and namedItem args in MimeTypeArray/PluginArray/Plugin non-optional

third_party/WebKit/Source/modules/plugins/PluginArray.idl

Index: third_party/WebKit/Source/modules/plugins/PluginArray.idl
diff --git a/third_party/WebKit/Source/modules/plugins/PluginArray.idl b/third_party/WebKit/Source/modules/plugins/PluginArray.idl
index 5bcbbcfad0306f9ed29a37c77d44be5e6c5d1413..1cedbb787a3087d141de896d474feeba455d27af 100644
--- a/third_party/WebKit/Source/modules/plugins/PluginArray.idl
+++ b/third_party/WebKit/Source/modules/plugins/PluginArray.idl
@@ -24,8 +24,8 @@
     ImplementedAs=DOMPluginArray
 ] interface PluginArray {
     readonly attribute unsigned long length;
-    getter Plugin? item([Default=Undefined] optional unsigned long index);
-    Plugin? namedItem([Default=Undefined] optional DOMString name);
-    [NotEnumerable, ImplementedAs=namedItem] getter Plugin ([Default=Undefined] optional DOMString name);
+    getter Plugin? item(unsigned long index);
+    Plugin? namedItem(DOMString name);
+    [NotEnumerable, ImplementedAs=namedItem] getter Plugin? (DOMString name);
     void refresh([Default=Undefined] optional boolean reload);
 };