Use memory compiler in compiler_helper.dart.

pkg/compiler/lib/src/commandline_options.dart

+// Copyright (c) 2015, 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 dart2js.cmdline.options;
+
+/// Commandline flags used in `dart2js.dart` and/or `apiimpl.dart`.
+class Flags {
+  static const String allowNativeExtensions = '--allow-native-extensions';
+  static const String analyzeAll = '--analyze-all';
+  static const String analyzeMain = '--analyze-main';
+  static const String analyzeOnly = '--analyze-only';
+  static const String analyzeSignaturesOnly = '--analyze-signatures-only';
+  static const String disableNativeLiveTypeAnalysis =
+      '--disable-native-live-type-analysis';
+  static const String disableTypeInference = '--disable-type-inference';
+  static const String dumpInfo = '--dump-info';
+  static const String enableCheckedMode = '--enable-checked-mode';
+  static const String enableConcreteTypeInference =
+      '--enable-concrete-type-inference';
+  static const String enableExperimentalMirrors =
+      '--enable-experimental-mirrors';
+  static const String fastStartup = '--fast-startup';
+  static const String fatalWarnings = '--fatal-warnings';
+  static const String generateCodeWithCompileTimeErrors =
+      '--generate-code-with-compile-time-errors';
+  static const String incrementalSupport = '--incremental-support';
+  static const String minify = '--minify';
+  static const String noFrequencyBasedMinification =
+      '--no-frequency-based-minification';
+  static const String noSourceMaps = '--no-source-maps';
+  static const String preserveComments = '--preserve-comments';
+  static const String preserveUris = '--preserve-uris';
+  static const String showPackageWarnings = '--show-package-warnings';
+  static const String suppressWarnings = '--suppress-warnings';
+  static const String terse = '--terse';
+  static const String testMode = '--test-mode';
+  static const String trustPrimitives = '--trust-primitives';
+  static const String trustTypeAnnotations = '--trust-type-annotations';
+  static const String useContentSecurityPolicy = '--csp';
+  static const String useCpsIr = '--use-cps-ir';
+  static const String verbose = '--verbose';
+}