Python 3 compatibility

test/mac/gyptest-app-assets-catalog.py

Index: test/mac/gyptest-app-assets-catalog.py
diff --git a/test/mac/gyptest-app-assets-catalog.py b/test/mac/gyptest-app-assets-catalog.py
index ca76b513aa735e01c547b413007913e48fe536aa..7b1c0f67deeb49a99d0652884373d991f478c356 100755
--- a/test/mac/gyptest-app-assets-catalog.py
+++ b/test/mac/gyptest-app-assets-catalog.py
@@ -8,6 +8,8 @@
 Verifies that app bundles are built correctly.
 """
 
+from __future__ import print_function
+
 import TestGyp
 import TestMac
 
@@ -17,12 +19,12 @@ import subprocess
 import sys
 
 if sys.platform == 'darwin':
-  print "This test is currently disabled: https://crbug.com/483696."
+  print("This test is currently disabled: https://crbug.com/483696.")
   sys.exit(0)
 
 def ExpectEq(expected, actual):
   if expected != actual:
-    print >>sys.stderr, 'Expected "%s", got "%s"' % (expected, actual)
+    print('Expected "%s", got "%s"' % (expected, actual), file=sys.stderr)
     test.fail_test()
 
 def ls(path):