Pass Redirect status higher than 307 through to the user

tests/html/html.status

 # Copyright (c) 2013, 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
 interactive_test: Skip # Must be run manually.
 dromaeo_smoke_test: Skip # Issue 14521, 8257
 cross_frame_test: Skip # Test reloads itself. Issue 18558
 
 [ $compiler == none && ($runtime == drt || $runtime == dartium || $runtime == ContentShellOnAndroid) ]
@@ skipping 85 matching lines @@
 speechrecognition_test/supported: Fail # TODO(dart2js-team): Please triage this failure.
 speechrecognition_test/types: Fail # TODO(dart2js-team): Please triage this failure.
 xhr_test/json: Fail # TODO(dart2js-team): Please triage this failure.
 
 [ $runtime == safarimobilesim ]
 element_offset_test/offset: RuntimeError # Issue 18573
 element_types_test/supported_meter: RuntimeError # Issue 18573
 
 [ $runtime == chrome ]
 touchevent_test/supported: Fail # Touch events are only supported on touch devices
-xhr_cross_origin_test: Pass, Fail # Issue 11884
-xhr_test: Pass, Fail # Issue 11884
 element_animate_test/omit_timing: Skip # Timing out inexplicably. Temporarily suppressing (alanknight)
 element_animate_test/timing_dict: Skip # Timing out inexplicably. Temporarily suppressing (alanknight)
 
 [ $runtime == chrome && ($system == windows || $system == macos) ]
 # New failure on Chrome 42.  Linux bots are not yet updated.
 element_animate_test/simple_timing: RuntimeError # Please triage this failure
 
 [$runtime == drt || $runtime == dartium || $runtime == chrome || $runtime == chromeOnAndroid || $runtime == ContentShellOnAndroid ]
 webgl_1_test: Pass, Fail # Issue 8219
 
@@ skipping 436 matching lines @@
 wheelevent_test: Crash # cannot compile methods that need interceptor calling convention.
 window_eq_test: Crash # cannot compile methods that need interceptor calling convention.
 window_mangling_test: Crash # cannot compile methods that need interceptor calling convention.
 window_nosuchmethod_test: Crash # cannot compile methods that need interceptor calling convention.
 window_test: Crash # cannot compile methods that need interceptor calling convention.
 worker_api_test: Crash # cannot compile methods that need interceptor calling convention.
 worker_test: Crash #  try/finally
 xhr_cross_origin_test: Crash #  try/finally
 xhr_test: Crash #  try/finally
 xsltprocessor_test: Crash #  try/finally