[autotest] Add Urllib3 package to external_packages.py

Some autotest servers don't have urllib3 installed.

BUG=None
TEST=pip uninstall urllib3; ./build_externals;
     inside python: import common, import urllib3,
     verified import succeeded.
DEPLOY=build_externals

Change-Id: I3c6c4280d06128b789e3a94c5c827c2630383e2a
Reviewed-on: https://chromium-review.googlesource.com/212139
Reviewed-by: Dan Shi <dshi@chromium.org>
Commit-Queue: Michael Liang <michaelliang@chromium.org>
Tested-by: Michael Liang <michaelliang@chromium.org>
diff --git a/utils/external_packages.py b/utils/external_packages.py
index 34a2d4a..09b4fec 100644
--- a/utils/external_packages.py
+++ b/utils/external_packages.py
@@ -1005,14 +1005,27 @@
     version = '1.0.0'
     url_filename = 'elasticsearch-%s.tar.gz' % version
     local_filename = url_filename
-    urls = ('https://pypi.python.org/packages/source/e/elasticsearch/%s' % (
-        url_filename),)
+    urls = ('https://pypi.python.org/packages/source/e/elasticsearch/%s' %
+            (url_filename),)
     hex_sum = 'e53e93eb2729c1dcd1bc3453d22340314027e900'
     _build_and_install = ExternalPackage._build_and_install_from_package
     _build_and_install_current_dir = (
             ExternalPackage._build_and_install_current_dir_setup_py)
 
 
+class Urllib3Package(ExternalPackage):
+    """elasticsearch-py package."""
+    version = '1.9'
+    url_filename = 'urllib3-%s.tar.gz' % version
+    local_filename = url_filename
+    urls = ('https://pypi.python.org/packages/source/u/urllib3/%s' %
+            (url_filename),)
+    hex_sum = '9522197efb2a2b49ce804de3a515f06d97b6602f'
+    _build_and_install = ExternalPackage._build_and_install_from_package
+    _build_and_install_current_dir = (
+            ExternalPackage._build_and_install_current_dir_setup_py)
+
+
 class ImagingLibraryPackage(ExternalPackage):
     """Python Imaging Library (PIL)."""
     version = '1.1.7'