Add slow marker for utils/dummy_compiler_test in checked mode.
Add slow marker for utils/dummy_compiler_test in checked mode.

Cutting the standard timeout in half caused this to now timeout instead of failing. 
Review URL: https://chromiumcodereview.appspot.com//10837280

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@10788 260f80e4-7a28-3924-810f-c04153c831b5

dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk