Add setters to legacy input_api.DEFAULT_*

Some PRESUBMIT.py scripts set DEFAULT_WHITE_LIST and DEFAULT_BLACK_LIST.
This patch adds support to override those defaults during transition
period.

R=apolito@google.com, ehmaldonado@chromium.org

Bug: 1098562
Change-Id: I5dfff253e61485d354a83f3f509d8a6d4d87dec6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2270717Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

presubmit_support.py

@@ -532,11 +532,21 @@ class InputApi(object):
   def DEFAULT_WHITE_LIST(self):
     return self.DEFAULT_ALLOW_LIST
 
+  # TODO(https://crbug.com/1098562): Remove once no longer used
+  @DEFAULT_WHITE_LIST.setter
+  def DEFAULT_WHITE_LIST(self, value):
+    self.DEFAULT_ALLOW_LIST = value
+
   # TODO(https://crbug.com/1098562): Remove once no longer used
   @property
   def DEFAULT_BLACK_LIST(self):
     return self.DEFAULT_BLOCK_LIST
 
+  # TODO(https://crbug.com/1098562): Remove once no longer used
+  @DEFAULT_BLACK_LIST.setter
+  def DEFAULT_BLACK_LIST(self, value):
+    self.DEFAULT_BLOCK_LIST = value
+
   def __init__(self, change, presubmit_path, is_committing,
       verbose, gerrit_obj, dry_run=None, thread_pool=None, parallel=False):
     """Builds an InputApi object.

tests/presubmit_unittest.py

@@ -1376,10 +1376,6 @@ class InputApiUnittest(PresubmitTestsBase):
     input_api = presubmit.InputApi(
         self.fake_change, './PRESUBMIT.py', False, None, False)
 
-    self.assertEqual(len(input_api.DEFAULT_ALLOW_LIST), 24)
-    self.assertEqual(len(input_api.DEFAULT_BLOCK_LIST), 12)
-    self.assertEqual(input_api.DEFAULT_ALLOW_LIST, input_api.DEFAULT_WHITE_LIST)
-    self.assertEqual(input_api.DEFAULT_BLOCK_LIST, input_api.DEFAULT_BLACK_LIST)
     for item in files:
       results = list(filter(input_api.FilterSourceFile, item[0]))
       for i in range(len(results)):
@@ -1390,6 +1386,30 @@ class InputApiUnittest(PresubmitTestsBase):
                                 for f in results]),
                         sorted(item[1]))
 
+  def testDefaultOverrides(self):
+    input_api = presubmit.InputApi(
+        self.fake_change, './PRESUBMIT.py', False, None, False)
+    self.assertEqual(len(input_api.DEFAULT_ALLOW_LIST), 24)
+    self.assertEqual(len(input_api.DEFAULT_BLOCK_LIST), 12)
+    self.assertEqual(input_api.DEFAULT_ALLOW_LIST, input_api.DEFAULT_WHITE_LIST)
+    self.assertEqual(input_api.DEFAULT_BLOCK_LIST, input_api.DEFAULT_BLACK_LIST)
+
+    input_api.DEFAULT_ALLOW_LIST = (r'.+\.c$',)
+    input_api.DEFAULT_BLOCK_LIST = (r'.+\.patch$', r'.+\.diff')
+    self.assertEqual(len(input_api.DEFAULT_ALLOW_LIST), 1)
+    self.assertEqual(len(input_api.DEFAULT_BLOCK_LIST), 2)
+    self.assertEqual(input_api.DEFAULT_ALLOW_LIST, input_api.DEFAULT_WHITE_LIST)
+    self.assertEqual(input_api.DEFAULT_BLOCK_LIST, input_api.DEFAULT_BLACK_LIST)
+
+    # Test backward compatiblity of setting old property names
+    # TODO(https://crbug.com/1098562): Remove once no longer used
+    input_api.DEFAULT_WHITE_LIST = ()
+    input_api.DEFAULT_BLACK_LIST = ()
+    self.assertEqual(len(input_api.DEFAULT_ALLOW_LIST), 0)
+    self.assertEqual(len(input_api.DEFAULT_BLOCK_LIST), 0)
+    self.assertEqual(input_api.DEFAULT_ALLOW_LIST, input_api.DEFAULT_WHITE_LIST)
+    self.assertEqual(input_api.DEFAULT_BLOCK_LIST, input_api.DEFAULT_BLACK_LIST)
+
   def testCustomFilter(self):
     def FilterSourceFile(affected_file):
       return 'a' in affected_file.LocalPath()