Add UseCounters for Selection methods that take null

third_party/WebKit/Source/core/editing/Selection.idl

 /*
  * Copyright (C) 2007 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Google Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 40 matching lines @@
     // TODO(philipj): The offset argument should not have a default value.
     [MeasureAs=SelectionCollapse, RaisesException, LegacyInterfaceTypeChecking] void collapse(Node? node, optional long offset = 0);
     // TODO(yoichio): The node argument should not be nullable. crbug.com/391673
     // TODO(philipj): The offset argument should not have a default value.
     [ImplementedAs=collapse, MeasureAs=SelectionSetPosition, RaisesException, LegacyInterfaceTypeChecking] void setPosition(Node? node, optional long offset = 0);
     [MeasureAs=SelectionCollapseToStart, RaisesException] void collapseToStart();
     [MeasureAs=SelectionCollapseToEnd, RaisesException] void collapseToEnd();
     // TODO(philipj): The offset argument should not have a default value.
     [MeasureAs=SelectionExtend, RaisesException] void extend(Node node, optional long offset = 0);
     // TODO(philipj): The arguments should be anchorNode, anchorOffset,
-    // focusNode and focusOffset, and none of them should be optional.
-    [MeasureAs=SelectionSetBaseAndExtent, RaisesException, LegacyInterfaceTypeChecking] void setBaseAndExtent([Default=Undefined] optional Node baseNode,
+    // focusNode and focusOffset, and none of them should be optional or
+    // nullable.
+    [MeasureAs=SelectionSetBaseAndExtent, RaisesException, LegacyInterfaceTypeChecking] void setBaseAndExtent([Default=Undefined] optional Node? baseNode,
                                                                                                               [Default=Undefined] optional long baseOffset,
-                                                                                                              [Default=Undefined] optional Node extentNode,
+                                                                                                              [Default=Undefined] optional Node? extentNode,
                                                                                                               [Default=Undefined] optional long extentOffset);
     [MeasureAs=SelectionSelectAllChildren, RaisesException] void selectAllChildren(Node node);
     [MeasureAs=SelectionDeleteDromDocument, CustomElementCallbacks] void deleteFromDocument();
     [MeasureAs=SelectionContainsNode] boolean containsNode(Node node, optional boolean allowPartialContainment = false);
     // TODO(philipj): The spec does not use [NotEnumerable]. See also:
     // https://codereview.chromium.org/345983004/
     // https://www.w3.org/Bugs/Public/show_bug.cgi?id=26179
     [MeasureAs=SelectionDOMString, NotEnumerable] stringifier DOMString();
 
     // Non-standard APIs
 
     // https://github.com/w3c/selection-api/issues/34
     [MeasureAs=SelectionBaseNode] readonly attribute Node? baseNode;
     [MeasureAs=SelectionBaseOffset] readonly attribute long baseOffset;
     [MeasureAs=SelectionExtentNode] readonly attribute Node? extentNode;
     [MeasureAs=SelectionExtentOffset] readonly attribute long extentOffset;
 
     // https://github.com/w3c/selection-api/issues/37
     [MeasureAs=SelectionModify] void modify([Default=Undefined] optional DOMString alter,
                                             [Default=Undefined] optional DOMString direction,
                                             [Default=Undefined] optional DOMString granularity);
 };