CQ: add a timeout for socket operations

commit-queue/commit_queue.py

Index: commit-queue/commit_queue.py
===================================================================
--- commit-queue/commit_queue.py	(revision 232827)
+++ commit-queue/commit_queue.py	(working copy)
@@ -14,6 +14,7 @@
 import os
 import shutil
 import signal
+import socket
 import sys
 import tempfile
 import time
@@ -146,6 +147,10 @@
 
 
 def main():
+  # Set a default timeout for sockets. This is critical when talking to remote
+  # services like AppEngine and buildbot.
+  socket.setdefaulttimeout(70.0)
+
   parser = optparse.OptionParser(
       description=sys.modules['__main__'].__doc__)
   project_choices = projects.supported_projects()