Drop py2 support in gclient and related files

python3 is the only supported version of python in depot_tools.

Bug: 1475402
Change-Id: I17174d7252b5cbf698700333d3cd561c6591d0a1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4809190
Reviewed-by: Aravind Vasudevan <aravindvasudev@google.com>
Commit-Queue: Gavin Mak <gavinmak@google.com>
Reviewed-by: Josip Sokcevic <sokcevic@chromium.org>
diff --git a/gclient_scm.py b/gclient_scm.py
index 9891e49..69ccc5f 100644
--- a/gclient_scm.py
+++ b/gclient_scm.py
@@ -4,8 +4,6 @@
 
 """Gclient-specific SCM-specific operations."""
 
-from __future__ import print_function
-
 import collections
 import contextlib
 import errno
@@ -15,21 +13,16 @@
 import platform
 import posixpath
 import re
+import shutil
 import sys
 import tempfile
 import threading
 import traceback
 
-try:
-  import urlparse
-except ImportError:  # For Py3 compatibility
-  import urllib.parse as urlparse
-
 import gclient_utils
 import gerrit_util
 import git_cache
 import scm
-import shutil
 import subprocess2