Cancel timout in test_runner.dart if RunningProcess transfers control to BatchRunnerProcess

tools/testing/dart/test_runner.dart

Index: tools/testing/dart/test_runner.dart
diff --git a/tools/testing/dart/test_runner.dart b/tools/testing/dart/test_runner.dart
index a95e1ee20d8ecff6a8ef2764cd9a8c1ad8225ba8..e712f7e6659a427d5a513601bfabcfde726da50b 100644
--- a/tools/testing/dart/test_runner.dart
+++ b/tools/testing/dart/test_runner.dart
@@ -564,6 +564,9 @@ class RunningProcess {
           !testCase.configuration['noBatch']) {
         // Note: processQueue will always be non-null for runtime == ie, ff,
         // safari, chrome, opera. (It is only null for runtime == vm)
+        // This RunningProcess object is done, and hands over control to
+        // BatchRunner.startTest(), which handles reporting, etc.
+        timeoutTimer.cancel();
         processQueue._getBatchRunner(testCase).startTest(testCase);
       } else {
         runCommand(testCase.commands[currentStep++], stepExitHandler);