gsutil: Use urllib2 instead of urllib.

This is similar to r247914 and r149742: urllib does not work with SSL
connections behind proxies, we need to use urllib2 instead. Doing this
should allow people behind proxies to download gsutils 4.7 after
r293413.

(Setting NOTRY here to be able to land the issue, otherwise the CQ fails when running some presubmit checks, see crbug.com/443232)

R=maruel@chromium.org, hinoka@chromium.org, pgervais@chromium.org, primiano@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/809053002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@293439 0039d316-1c4b-4281-b951-d872f2087c98

gsutil.py

@@ -7,15 +7,15 @@
 
 
 import argparse
-import shutil
-import zipfile
-import hashlib
 import base64
-import os
-import sys
+import hashlib
 import json
-import urllib
+import os
+import shutil
 import subprocess
+import sys
+import urllib2
+import zipfile
 
 
 GSUTIL_URL = 'https://storage.googleapis.com/pub/'
@@ -67,7 +67,7 @@ def download_gsutil(version, target_dir):
     local_md5 = md5_calc.hexdigest()
 
     metadata_url = '%s%s' % (API_URL, filename)
-    metadata = json.load(urllib.urlopen(metadata_url))
+    metadata = json.load(urllib2.urlopen(metadata_url))
     remote_md5 = base64.b64decode(metadata['md5Hash'])
 
     if local_md5 == remote_md5:
@@ -76,7 +76,7 @@ def download_gsutil(version, target_dir):
 
   # Do the download.
   url = '%s%s' % (GSUTIL_URL, filename)
-  u = urllib.urlopen(url)
+  u = urllib2.urlopen(url)
   with open(target_filename, 'wb') as f:
     while True:
       buf = u.read(4096)

tests/gsutil_test.py

@@ -16,7 +16,7 @@ import base64
 import tempfile
 import json
 import os
-import urllib
+import urllib2
 
 
 # Add depot_tools to path
@@ -71,15 +71,15 @@ class GsutilUnitTests(unittest.TestCase):
   def setUp(self):
     self.fake = FakeCall()
     self.tempdir = tempfile.mkdtemp()
-    self.old_urlopen = getattr(urllib, 'urlopen')
+    self.old_urlopen = getattr(urllib2, 'urlopen')
     self.old_call = getattr(gsutil, 'call')
-    setattr(urllib, 'urlopen', self.fake)
+    setattr(urllib2, 'urlopen', self.fake)
     setattr(gsutil, 'call', self.fake)
 
   def tearDown(self):
     self.assertEqual(self.fake.expectations, [])
     shutil.rmtree(self.tempdir)
-    setattr(urllib, 'urlopen', self.old_urlopen)
+    setattr(urllib2, 'urlopen', self.old_urlopen)
     setattr(gsutil, 'call', self.old_call)
 
   def test_download_gsutil(self):