Remove meaningless uses of [TypeChecking=Nullable]

Source/core/page/Selection.idl

Index: Source/core/page/Selection.idl
diff --git a/Source/core/page/Selection.idl b/Source/core/page/Selection.idl
index db35b80a086e7236d47655178b9b19d4f5b01da5..b28b53ecb00f5b33453896f942f42c750bfb24fe 100644
--- a/Source/core/page/Selection.idl
+++ b/Source/core/page/Selection.idl
@@ -41,8 +41,8 @@
     readonly attribute boolean isCollapsed;
     readonly attribute long rangeCount;
 
-    [RaisesException, TypeChecking=Interface|Nullable] void collapse(Node node,
-                                                        optional long offset);
+    [RaisesException, TypeChecking=Interface] void collapse(Node node,
+                                                            optional long offset);
     [RaisesException] void collapseToEnd();
     [RaisesException] void collapseToStart();
 
@@ -77,8 +77,8 @@
                                                                                  [Default=Undefined] optional long baseOffset,
                                                                                  [Default=Undefined] optional Node extentNode,
                                                                                  [Default=Undefined] optional long extentOffset);
-    [ImplementedAs=collapse, MeasureAs=SelectionSetPosition, RaisesException, TypeChecking=Interface|Nullable] void setPosition(Node node,
-                                                                                                                                optional long offset);
+    [ImplementedAs=collapse, MeasureAs=SelectionSetPosition, RaisesException, TypeChecking=Interface] void setPosition(Node node,
+                                                                                                                       optional long offset);
 
     // IE extentions
     // http://msdn.microsoft.com/en-us/library/ms535869(VS.85).aspx