Hook async/await compiler into pub and use it.

sdk/lib/_internal/pub/lib/src/command/run.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 pub.command.run;
 
 import 'dart:async';
 
 import '../command.dart';
 import '../executable.dart';
 import '../io.dart';
 import '../utils.dart';
 
 /// Handles the `run` pub command.
 class RunCommand extends PubCommand {
   bool get takesArguments => true;
   bool get allowTrailingOptions => false;
   String get description => "Run an executable from a package.\n"
       "NOTE: We are currently optimizing this command's startup time.";
   String get usage => "pub run <executable> [args...]";
 
-  Future onRun() {
+  Future onRun() async {
     if (commandOptions.rest.isEmpty) {
       usageError("Must specify an executable to run.");
     }
 
     var package = entrypoint.root.name;
     var executable = commandOptions.rest[0];
     var args = commandOptions.rest.skip(1).toList();
 
     // A command like "foo:bar" runs the "bar" script from the "foo" package.
     // If there is no colon prefix, default to the root package.
     if (executable.contains(":")) {
       var components = split1(executable, ":");
       package = components[0];
       executable = components[1];
     }
 
-    return runExecutable(this, entrypoint, package, executable, args)
-        .then(flushThenExit);
+    var exitCode = await runExecutable(this, entrypoint, package, executable,
+        args);
+    flushThenExit(exitCode);

[nweiz, 2014/08/27 20:10:07]

We should await on this.

[Bob Nystrom, 2014/08/27 21:35:32]

Done.

   }
 }