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

dart/tests/standalone/standalone.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.
 
 timeout_test: Skip  # Timeout test for testing the test runner.
 fail_test: Fail, OK # Fails intentionally
 out_of_memory_test: Skip # Issue 2345
 
 package/invalid_uri_test: Fail, OK # Fails intentionally
 
@@ skipping 28 matching lines @@
 io/http_connection_header_test: Pass, Fail  # Issue 2959
 
 [ $compiler == none && $runtime == drt ]
 io/*: Skip # Don't run tests using dart:io in the browser
 crypto/*: Skip # Don't run tests using dart:io in the browser
 package/*: Skip # Do not run those in Dartium.
 
 [ $compiler == dartc]
 *: Skip
 
-[ $compiler == frog || ($compiler == dart2js && $runtime == drt) ]
+[ $compiler == frog ]
 *: Skip
 
 [ $arch == x64 ]
 medium_integer_test: Fail # Issue 1146.
 
 
 [ $arch == arm ]
 *: Skip
 
 
 [ $arch == simarm ]
 *: Skip
 
 [ $compiler == dart2js ]
 medium_integer_test: Fail, OK # cannot resolve type Mint
 io/test_extension_test: Fail, OK # dart-ext:test_extension: Illegal argument(s): dart-ext:test_extension
 io/test_runner_test: Fail, OK # library not found dart:builtin
 
 [ $compiler == dart2js && $runtime == d8 ]
 assert_test: Fail # Assert not implemented
 byte_array_test: Fail, OK # ByteArray
 deoptimization_test: Fail, OK # Requires bigint.
 out_of_memory_test: Fail, OK # d8 handles much larger arrays than Dart VM.
 io/http_parser_test: Fail, OK # ByteArray
 io/options_test: Fail, OK # Cannot pass options to d8.
 
 [ $compiler == dart2js && $runtime == none ]
 fail_test: Skip # fails only at runtime, overrides default expectation from standalone.status
 io/options_test: Fail
+
+[$compiler == dart2js && $browser ]
+*: Skip