Throw when blocking top-level navigation.

third_party/WebKit/Source/core/frame/Location.idl

 /*
  * Copyright (C) 2008 Apple 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.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 30 matching lines @@
     [CallWith=(CurrentWindow,EnteredWindow), DoNotCheckSecurity, RaisesException] void replace(DOMString url);
     [CallWith=CurrentWindow] void reload();
 
     // TODO(foolip): ancestorOrigins should have [SameObject] and be of type
     // DOMString[], i.e. it should return the same array every time.
     [Measure] readonly attribute DOMStringList ancestorOrigins;
 
     // TODO(foolip): Per spec, Location implements URLUtils. The below is
     // mostly like the URLUtils interface, but with some members missing and
     // using DOMString instead of USVString.
-    [SetterCallWith=(CurrentWindow,EnteredWindow), DoNotCheckSecurity=Setter] attribute DOMString href;
+    [SetterCallWith=(CurrentWindow,EnteredWindow), DoNotCheckSecurity=Setter, RaisesException=Setter] attribute DOMString href;
     [NotEnumerable, ImplementedAs=href] DOMString toString();
     readonly attribute DOMString origin;
 
     [SetterCallWith=(CurrentWindow,EnteredWindow), RaisesException=Setter] attribute DOMString protocol;
-    [SetterCallWith=(CurrentWindow,EnteredWindow)] attribute DOMString host;
-    [SetterCallWith=(CurrentWindow,EnteredWindow)] attribute DOMString hostname;
-    [SetterCallWith=(CurrentWindow,EnteredWindow)] attribute DOMString port;
-    [SetterCallWith=(CurrentWindow,EnteredWindow)] attribute DOMString pathname;
-    [SetterCallWith=(CurrentWindow,EnteredWindow)] attribute DOMString search;
-    [SetterCallWith=(CurrentWindow,EnteredWindow)] attribute DOMString hash;
+    [SetterCallWith=(CurrentWindow,EnteredWindow), RaisesException=Setter] attribute DOMString host;
+    [SetterCallWith=(CurrentWindow,EnteredWindow), RaisesException=Setter] attribute DOMString hostname;
+    [SetterCallWith=(CurrentWindow,EnteredWindow), RaisesException=Setter] attribute DOMString port;
+    [SetterCallWith=(CurrentWindow,EnteredWindow), RaisesException=Setter] attribute DOMString pathname;
+    [SetterCallWith=(CurrentWindow,EnteredWindow), RaisesException=Setter] attribute DOMString search;
+    [SetterCallWith=(CurrentWindow,EnteredWindow), RaisesException=Setter] attribute DOMString hash;
 
     // TODO(foolip): Location does not have a valueOf() override in the spec.
     // See the comment in Location.h for the purpose of this.
     [NotEnumerable, CallWith=ThisValue] any valueOf();
 };