Remove negated variables now that we support "!".

tools/testing/dart/environment.dart

 // Copyright (c) 2017, 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.
 
 import 'configuration.dart';
 
 typedef String _LookUpFunction(Configuration configuration);
 typedef bool _BoolLookUpFunction(Configuration configuration);
 
 // TODO(29756): Instead of synthesized negated variables like "unchecked",
@@ skipping 12 matching lines @@
   "host_unchecked": new _Variable.bool((c) => !c.isHostChecked),
   "hot_reload": new _Variable.bool((c) => c.hotReload),
   "hot_reload_rollback": new _Variable.bool((c) => c.hotReloadRollback),
   "ie": new _Variable.bool((c) => c.runtime.isIE),
   "jscl": new _Variable.bool((c) => c.runtime.isJSCommandLine),
   "minified": new _Variable.bool((c) => c.isMinified),
   "mode": new _Variable((c) => c.mode.name, Mode.names),
   "runtime": new _Variable(_runtimeName, Runtime.names),
   "strong": new _Variable.bool((c) => c.isStrong),
   "system": new _Variable((c) => c.system.name, System.names),
-  "unchecked": new _Variable.bool((c) => !c.isChecked),
-  "unminified": new _Variable.bool((c) => !c.isMinified),
   "use_sdk": new _Variable.bool((c) => c.useSdk)
 };
 
 /// Gets the name of the runtime as it appears in status files.
 String _runtimeName(Configuration configuration) {
   // TODO(rnystrom): Handle "ff" being used as the name for firefox. We don't
   // want to make the Runtime itself use that as the name because it appears
   // elsewhere in test.dart and we want those other places to show "firefox".
   if (configuration.runtime == Runtime.firefox) return 'ff';
 
@@ skipping 61 matching lines @@
   _Variable(this._lookUp, Iterable<String> allowed)
       : allowedValues = allowed.toList();
 
   /// Creates a Boolean variable with allowed values "true" and "false".
   _Variable.bool(_BoolLookUpFunction lookUp)
       : _lookUp = ((configuration) => lookUp(configuration).toString()),
         allowedValues = const ["true", "false"];
 
   String lookUp(Configuration configuration) => _lookUp(configuration);
 }