Make the DOMStringMap deleter return type void

Source/core/dom/DOMStringMap.idl

Index: Source/core/dom/DOMStringMap.idl
diff --git a/Source/core/dom/DOMStringMap.idl b/Source/core/dom/DOMStringMap.idl
index 0b8031ab06adfbf6740be0c96a343e42e951007a..2034eac6c57492a2eeaad1a0c9d0b91e9f52e1ea 100644
--- a/Source/core/dom/DOMStringMap.idl
+++ b/Source/core/dom/DOMStringMap.idl
@@ -32,12 +32,11 @@
 ] interface DOMStringMap {
     [ImplementedAs=item] getter DOMString (DOMString name);
     [RaisesException] setter void (DOMString name, DOMString value);
-    // FIXME: The deleter return type should be void. crbug.com/462920
-    deleter boolean (DOMString name);
+    deleter void (DOMString name);
 
     // FIXME: The indexed getter, setter and deleter are not in the
     // spec and simply converts the index to a string.
     [NotEnumerable] getter DOMString (unsigned long index);
     [RaisesException] setter void (unsigned long index, DOMString value);
-    deleter boolean (unsigned long index);
+    deleter void (unsigned long index);
 };