Add command for updating the host name in WPR archive

httparchive.py

Index: httparchive.py
diff --git a/httparchive.py b/httparchive.py
index 32dbe9771f27a77be6673ce186f6d4923c341668..f8e52f58d8df901d8b5bdded43cbd57554e55cf8 100755
--- a/httparchive.py
+++ b/httparchive.py
@@ -1061,6 +1061,19 @@ def main():
   elif command == 'edit':
     http_archive.edit(options.command, options.host, options.full_path)
     http_archive.Persist(replay_file)
+  elif command == 'remap-host':
+    old_host = args[2]
+    new_host = args[3]
+    update_count = 0
+    for req in http_archive:
+      if req.host == old_host:
+        req.host = new_host
+        update_count += 1
+    updated_file_path = replay_file + '.updated'
+    http_archive.Persist(updated_file_path)
+    print 'Updated %i hosts of address %s to address %s' % (
+        update_count, old_host, new_host)
+    print 'The updated WPR is saved as %s' % updated_file_path
   else:
     option_parser.error('Unknown command "%s"' % command)
   return 0