update DDC to use analyzer extractDefinedVariables

pkg/dev_compiler/lib/src/compiler/command.dart

Index: pkg/dev_compiler/lib/src/compiler/command.dart
diff --git a/pkg/dev_compiler/lib/src/compiler/command.dart b/pkg/dev_compiler/lib/src/compiler/command.dart
index fb6a29a96209499401e0915ffb3fdf3448e2e778..8a4f92ab6fab09e7431a135ac7caa355b3f2c6ca 100644
--- a/pkg/dev_compiler/lib/src/compiler/command.dart
+++ b/pkg/dev_compiler/lib/src/compiler/command.dart
@@ -3,6 +3,8 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:io';
+import 'package:analyzer/src/command_line/arguments.dart'
+    show extractDefinedVariables;
 import 'package:analyzer/src/generated/source.dart' show Source;
 import 'package:analyzer/src/summary/package_bundle_reader.dart'
     show InSummarySource;
@@ -10,7 +12,7 @@ import 'package:args/args.dart' show ArgParser, ArgResults;
 import 'package:args/command_runner.dart' show UsageException;
 import 'package:path/path.dart' as path;
 
-import '../analyzer/context.dart' show AnalyzerOptions, parseDeclaredVariables;
+import '../analyzer/context.dart' show AnalyzerOptions;
 import 'compiler.dart' show BuildUnit, CompilerOptions, ModuleCompiler;
 import 'module_builder.dart';
 
@@ -26,7 +28,8 @@ int compile(List<String> args, {void printFn(Object obj)}) {
   ArgResults argResults;
   var declaredVars = <String, String>{};
   try {
-    argResults = _argParser().parse(parseDeclaredVariables(args, declaredVars));
+    args = extractDefinedVariables(args, declaredVars);
+    argResults = _argParser().parse(args);
     _verbose = argResults['verbose'];
   } on FormatException catch (error) {
     printFn('$error\n\n$_usageMessage');