Fix keyboard interrupt in test driver.

tools/testrunner/local/pool.py

Index: tools/testrunner/local/pool.py
diff --git a/tools/testrunner/local/pool.py b/tools/testrunner/local/pool.py
index 8f629f9e4a3862418665f5f8d4bce0e10a20f879..602a2d4b3097b7af0bfd331d6c67b013178e1f01 100644
--- a/tools/testrunner/local/pool.py
+++ b/tools/testrunner/local/pool.py
@@ -134,3 +134,13 @@ class Pool():
 
     for p in self.processes:
       p.join()
+
+    # Drain the queues to prevent failures when queues are garbage collected.
+    try:
+      while True: self.work_queue.get(False)
+    except:
+      pass
+    try:
+      while True: self.done_queue.get(False)
+    except:
+      pass