convert to print_function

BUG=chromium:414895
TEST=`./cbuildbot/run_tests` passes
TEST=`cros lint` passes (it complains if print is used incorrectly)
TEST=`cbuildbot chromiumos-sdk` passes
TEST=`cbuildbot lumpy-release` passes

Change-Id: I67e7e1290b03a16525e0c2b1afa74ebbd8d3508f
Reviewed-on: https://chromium-review.googlesource.com/218572
Reviewed-by: David James <davidjames@chromium.org>
Reviewed-by: Yu-Ju Hong <yjhong@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/cros_extract_deps.py b/scripts/cros_extract_deps.py
index deb3c20..dab2c7f 100644
--- a/scripts/cros_extract_deps.py
+++ b/scripts/cros_extract_deps.py
@@ -4,6 +4,8 @@
 
 """Command to extract the dependancy tree for a given package."""
 
+from __future__ import print_function
+
 import json
 import portage  # pylint: disable=F0401
 
@@ -164,4 +166,4 @@
   deps_list = FlattenDepTree(deps_tree)
   if known_args.format == "cpe":
     deps_list = ExtractCPEList(deps_list)
-  print json.dumps(deps_list, sort_keys=True, indent=2)
+  print(json.dumps(deps_list, sort_keys=True, indent=2))