Enabled class name minification in production mode.

compiler/java/com/google/dart/runner/DartRunner.java

Index: compiler/java/com/google/dart/runner/DartRunner.java
===================================================================
--- compiler/java/com/google/dart/runner/DartRunner.java	(revision 369)
+++ compiler/java/com/google/dart/runner/DartRunner.java	(working copy)
@@ -337,7 +337,9 @@
       final DartRunnerOptions options, DartCompilerListener listener) throws RunnerError {
     Backend backend;
     if (options.shouldOptimize()) {
-      backend = new ClosureJsBackend(options.generateHumanReadableOutput());
+      backend = new ClosureJsBackend(
+          options.developerModeChecks(),
+          options.generateHumanReadableOutput());
     } else {
       backend = new JavascriptBackend();
     }