IDL: make optional arguments (without default) explicit sometimes

Source/core/editing/Selection.idl

Index: Source/core/editing/Selection.idl
diff --git a/Source/core/editing/Selection.idl b/Source/core/editing/Selection.idl
index dc27b0d9bfbe2d06112f4fcaed18e339ecad9d87..56a842039f4fc569db0e6de60357b0f1fadac7e6 100644
--- a/Source/core/editing/Selection.idl
+++ b/Source/core/editing/Selection.idl
@@ -54,12 +54,12 @@
     // http://crbug.com/384966
     [RaisesException, TypeChecking=Interface] void extend(Node node, optional long offset);
 
-    [RaisesException] void selectAllChildren([Default=Undefined] optional Node node);
+    [RaisesException] void selectAllChildren(optional Node node);
     [CustomElementCallbacks] void deleteFromDocument();
 
     readonly attribute long rangeCount;
-    [RaisesException] Range getRangeAt([Default=Undefined] optional long index);
-    void addRange([Default=Undefined] optional Range range);
+    [RaisesException] Range getRangeAt(optional long index);
+    void addRange(optional Range range);
     void removeAllRanges();
 
     [NotEnumerable] stringifier;
@@ -68,7 +68,7 @@
     // https://developer.mozilla.org/En/DOM/Selection
     //
     // FIXME: Add use counters.
-    boolean containsNode([Default = Undefined] optional Node node, [Default = Undefined] optional boolean allowPartial);
+    boolean containsNode(optional Node node, optional boolean allowPartial = false);
 
     // WebKit extensions
     [MeasureAs=SelectionBaseNode] readonly attribute Node baseNode;
@@ -80,13 +80,13 @@
     // IE's type accessor returns "none", "text" and "control"
     [MeasureAs=SelectionType] readonly attribute DOMString type;
 
-    [MeasureAs=SelectionModify] void modify([Default=Undefined] optional DOMString alter,
-                                            [Default=Undefined] optional DOMString direction,
-                                            [Default=Undefined] optional DOMString granularity);
-    [MeasureAs=SelectionSetBaseAndExtent, RaisesException] void setBaseAndExtent([Default=Undefined] optional Node baseNode,
-                                                                                 [Default=Undefined] optional long baseOffset,
-                                                                                 [Default=Undefined] optional Node extentNode,
-                                                                                 [Default=Undefined] optional long extentOffset);
+    [MeasureAs=SelectionModify] void modify(optional DOMString alter,
+                                            optional DOMString direction,
+                                            optional DOMString granularity);
+    [MeasureAs=SelectionSetBaseAndExtent, RaisesException] void setBaseAndExtent(optional Node baseNode,
+                                                                                 optional long baseOffset,
+                                                                                 optional Node extentNode,
+                                                                                 optional long extentOffset);
     [ImplementedAs=collapse, MeasureAs=SelectionSetPosition, RaisesException, TypeChecking=Interface] void setPosition(Node node,
                                                                                                                        optional long offset);