Add a browser configuration to avoid repeating (runtime == 'ff' || runtime == 'ie' || ...).

dart/tests/co19/co19-leg.status

 # Copyright (c) 2011, 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.
 
 [ $compiler == dart2js && $system == macos && $runtime == d8 ]
 LibTest/core/Math/acos_A01_t01: Fail, OK
 LibTest/core/Math/asin_A01_t01: Fail, OK
 LibTest/core/Math/atan_A01_t01: Fail, OK
 
 
@@ skipping 46 matching lines @@
 
 LibTest/core/TimeZone/TimeZone.local_A01_t01: Skip
 LibTest/core/TimeZone/TimeZone.utc_A01_t01: Skip
 
 
 [ $compiler == dart2js && $checked ]
 # Leg does not support checked mode yet.
 *: Skip
 
 
-[ $compiler == dart2js && $runtime == drt]
+[ $compiler == dart2js && $browser ]
 *: Skip
 
 
 #
 # Issues with co19 test suite.
 #
 # If you add anything here, either file a bug against the Dart
 # langauge specification, co19 test suite, or add a comment that ahe@
 # can understand so he can file a bug later.
 #
@@ skipping 466 matching lines @@
 Language/12_Libraries_and_Scripts/12_Libraries_and_Scripts_A05_t03: Fail, OK # @compile-error
 Language/12_Libraries_and_Scripts/12_Libraries_and_Scripts_A07_t02: Fail, OK # @compile-error
 Language/12_Libraries_and_Scripts/1_Imports_A03_t05: Fail, OK # @compile-error
 Language/12_Libraries_and_Scripts/1_Imports_A05_t01: Fail, OK # @compile-error
 Language/12_Libraries_and_Scripts/1_Imports_A07_t01: Fail, OK # @compile-error
 Language/12_Libraries_and_Scripts/1_Imports_A07_t02: Fail, OK # @compile-error
 Language/12_Libraries_and_Scripts/2_Includes_A01_t01: Fail, OK # @compile-error
 Language/12_Libraries_and_Scripts/2_Includes_A03_t03: Fail, OK # @compile-error
 Language/13_Types/1_Static_Types_A02_t08: Fail, OK # @compile-error
 Language/13_Types/7_Type_Void_A01_t02: Fail, OK # @compile-error