Make test runner more chatty to avoid it getting killed by buildbot.

tools/testrunner/local/progress.py

Index: tools/testrunner/local/progress.py
diff --git a/tools/testrunner/local/progress.py b/tools/testrunner/local/progress.py
index 2616958c47887f4fa427627d57fde41ad36cb15b..f47fa3af84848d08cdf4c31be49cae3f2ac22d5d 100644
--- a/tools/testrunner/local/progress.py
+++ b/tools/testrunner/local/progress.py
@@ -66,6 +66,9 @@ class ProgressIndicator(object):
   def HasRun(self, test, has_unexpected_output):
     pass
 
+  def Heartbeat(self):
+    pass
+
   def PrintFailureHeader(self, test):
     if test.suite.IsNegativeTest(test):
       negative_marker = '[negative] '
@@ -128,6 +131,10 @@ class VerboseProgressIndicator(SimpleProgressIndicator):
       outcome = 'pass'
     print 'Done running %s: %s' % (test.GetLabel(), outcome)
 
+  def Heartbeat(self):
+    print 'Still working...'
+    sys.stdout.flush()
+
 
 class DotsProgressIndicator(SimpleProgressIndicator):