Add --dart2js-options flag to test command

tools/testing/dart/compiler_configuration.dart

 // Copyright (c) 2014, 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.
 
 library compiler_configuration;
 
 import 'dart:io' show
     Platform;
 
 import 'runtime_configuration.dart' show
@@ skipping 55 matching lines @@
         return new AnalyzerCompilerConfiguration(
             'dartanalyzer', isDebug: isDebug, isChecked: isChecked,
             isHostChecked: isHostChecked, useSdk: useSdk);
       case 'dart2analyzer':
         return new DartBasedAnalyzerCompilerConfiguration(
             isDebug: isDebug, isChecked: isChecked,
             isHostChecked: isHostChecked, useSdk: useSdk);
       case 'dart2js':
         return new Dart2jsCompilerConfiguration(
             isDebug: isDebug, isChecked: isChecked,
-            isHostChecked: isHostChecked, useSdk: useSdk, isCsp: isCsp);
+            isHostChecked: isHostChecked, useSdk: useSdk, isCsp: isCsp,
+            extraDart2jsOptions:
+                TestUtils.getExtraOptions(configuration, 'dart2js_options'));
       case 'dart2dart':
         return new Dart2dartCompilerConfiguration(
             isDebug: isDebug, isChecked: isChecked,
             isHostChecked: isHostChecked, useSdk: useSdk);
       case 'none':
         return new NoneCompilerConfiguration(
             isDebug: isDebug, isChecked: isChecked,
             isHostChecked: isHostChecked, useSdk: useSdk);
       default:
         throw "Unknown compiler '$compiler'";
@@ skipping 128 matching lines @@
 
     Uri absoluteBuildDir = Uri.base.resolveUri(nativeDirectoryToUri(buildDir));
     return [absoluteBuildDir.resolve(
           'dart-sdk/bin/snapshots/dart2js.dart.snapshot')];
   }
 }
 
 /// Configuration for dart2js compiler.
 class Dart2jsCompilerConfiguration extends Dart2xCompilerConfiguration {
   final bool isCsp;
+  final List<String> extraDart2jsOptions;
 
   Dart2jsCompilerConfiguration({
       bool isDebug,
       bool isChecked,
       bool isHostChecked,
       bool useSdk,
-      bool this.isCsp})
+      bool this.isCsp,
+      this.extraDart2jsOptions})
       : super(
           'dart2js',
           isDebug: isDebug, isChecked: isChecked,
           isHostChecked: isHostChecked, useSdk: useSdk);
 
   int computeTimeoutMultiplier() {
     int multiplier = 1;
     if (isDebug) multiplier *= 4;
     if (isChecked) multiplier *= 2;
     if (isHostChecked) multiplier *= 16;
     return multiplier;
   }
 
   CommandArtifact computeCompilationArtifact(
       String buildDir,
       String tempDir,
       CommandBuilder commandBuilder,
       List arguments,
       Map<String, String> environmentOverrides) {
     return new CommandArtifact(
         <Command>[
             this.computeCompilationCommand(
                 '$tempDir/out.js',
                 buildDir,
                 CommandBuilder.instance,
-                arguments,
+                []..addAll(arguments)..addAll(extraDart2jsOptions),
                 environmentOverrides)],
         '$tempDir/out.js',
         'application/javascript');
   }
 
   List<String> computeRuntimeArguments(
       RuntimeConfiguration runtimeConfiguration,
       String buildDir,
       TestInformation info,
       List<String> vmOptions,
@@ skipping 114 matching lines @@
       bool isDebug,
       bool isChecked,
       bool isHostChecked,
       bool useSdk})
       : super(
           'dart2analyzer', isDebug: isDebug, isChecked: isChecked,
           isHostChecked: isHostChecked, useSdk: useSdk);
 
   String computeCompilerPath(String buildDir) => 'editor/tools/analyzer';
 }