Convert print statements to Python 3 style

Ran "2to3 -w -n -f print ./" and manually added imports.
Ran "^\s*print " and "\s+print " to find batch/shell scripts, comments and the like with embedded code, and updated them manually.
Also manually added imports to files, which used print as a function, but were missing the import.

The scripts still work with Python 2.
There are no intended behaviour changes.

Bug: 942522
Change-Id: Id777e4d4df4adcdfdab1b18bde89f235ef491b9f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1595684
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Auto-Submit: Raul Tambre <raul@tambre.ee>
diff --git a/tests/git_cl_test.py b/tests/git_cl_test.py
index 63ac18f..36c0997 100755
--- a/tests/git_cl_test.py
+++ b/tests/git_cl_test.py
@@ -1192,7 +1192,7 @@
           short_hostname=short_hostname,
           labels=labels)
     # Uncomment when debugging.
-    # print '\n'.join(map(lambda x: '%2i: %s' % x, enumerate(self.calls)))
+    # print('\n'.join(map(lambda x: '%2i: %s' % x, enumerate(self.calls))))
     git_cl.main(['upload'] + upload_args)
 
   def test_gerrit_upload_without_change_id(self):