Add token to stderr as well as stdout for batch processing.

compiler/java/com/google/dart/compiler/UnitTestBatchRunner.java

Index: compiler/java/com/google/dart/compiler/UnitTestBatchRunner.java
diff --git a/compiler/java/com/google/dart/compiler/UnitTestBatchRunner.java b/compiler/java/com/google/dart/compiler/UnitTestBatchRunner.java
index ab8d474fabb5dac4b819e1f3c9ff550475ba2688..453fc9b0e99e0edb96ead1a7405434fa493fee84 100644
--- a/compiler/java/com/google/dart/compiler/UnitTestBatchRunner.java
+++ b/compiler/java/com/google/dart/compiler/UnitTestBatchRunner.java
@@ -45,6 +45,9 @@ public class UnitTestBatchRunner {
         if (!result) {
           testsFailed++;
         }
+        // Write stderr end token and flush.
+        System.err.println(">>> EOF STDERR");
+        System.err.flush();
         System.out.println(">>> TEST " + (result ? "PASS" : "FAIL") + " "
             + (System.currentTimeMillis() - testStart) + "ms");
         System.out.flush();