Minimal fix to get cross frame tests working, take #2.

tests/html/html.status

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 event_test: Skip  # Issue 1996
 webgl_1_test: Skip  # Issue 1495
 xmldocument_test: Skip  # XML in dart:html is incomplete
 xmlelement_test: Skip  # XML in dart:html is incomplete
 measurement_test: Pass, Fail  # Issue 1940
 svgelement2_test: Skip # Issue 2998
 
 [ $compiler == none && ($runtime == drt || $runtime == dartium) ]
 request_animation_frame_test: Skip   # drt hangs; requestAnimationFrame not implemented
 indexeddb_3_test: Fail  # exception not caught - not 'is IDBDatabaseException' ?
 indexeddb_4_test: Fail  # exception not caught - not 'is IDBDatabaseException' ?
 svgelement2_test: Fail  # started to timeout, needs investigation.
 
 [ $compiler == none && ($runtime == drt || $runtime == dartium) && $mode == debug ]
 native_gc_test: Skip  # Issue 2538. Too slow in debug.
 
 [ $compiler == none && $runtime == drt && $system == windows]
 audiocontext_test: Skip
 
 [ $compiler == frog && $runtime == drt ]
 html_test: Skip   # Issue 2657
 request_animation_frame_test: Skip   # drt hangs
 
 [ $compiler == frog && ($runtime == drt || $runtime == ie || $runtime == safari || $runtime == ff || $runtime == chrome || $runtime == opera) ]
 window_nosuchmethod_test: Fail # Issue 1837, frog puts top-level members in the global JS namespace.
-cross_frame_test: Fail # Issue 2774, iframe.contentDocument is accessible in dart:html frog.
-inner_frame_test: Fail # Issue 2774
 
 [ $runtime == ie || $runtime == safari || $runtime == ff || $runtime == chrome || $runtime == opera || ($runtime == drt && $compiler == frog)]
 # TODO(vsm): Triage DOM tests.
 dom_isolates_test: Fail
 indexeddb_2_test: Fail  # Issue 1883 - IndexedDB methods don't handle maps correctly.
 window_open_test: Fail
 
 [ $runtime == dartium || $runtime == chrome || $runtime == ie || $runtime == safari || $runtime == ff || $runtime == opera ]
 history_test: Fail
 
@@ skipping 103 matching lines @@
 [ $compiler == dart2js && $runtime == none ]
 *: Fail, Pass # TODO(ahe): Triage these tests.
 
 [ $compiler == dart2js ]
 dom_isolates_test: Fail # error: cannot resolve spawnDomIsolate
 
 [ $compiler == dart2js && ($runtime == drt || $runtime == chrome || $runtime == ff) ]
 request_animation_frame_test: Skip # Async test hangs.
 isolates_test: Skip   # Timeout because leg does not support web workers.
 typed_arrays_1_test: Fail # dart2js doesn't support is checks with generic types.
-cross_frame_test: Fail # Issue 2774, iframe.contentDocument is accessible in dart:html
-inner_frame_test: Fail # Issue 2774
 indexeddb_3_test: Fail  # TypeError: Object #<IDBCursorWithValue> has no method 'continueFunction'
 indexeddb_4_test: Fail  # TypeError: Object #<IDBCursorWithValue> has no method 'continueFunction'
 
 # DOM errors.
 indexeddb_2_test: Fail # Uncaught error
 window_open_test: Fail # TypeError: Object [object Window] has no method 'close$0'