Add debugging info when gclient deletes an old DEPS entry.

To help figure out why it decided to do so.

BUG=823586

Change-Id: I93d7c9f7af6145ee0ebd9f5ad4483f27925e84d6
Reviewed-on: https://chromium-review.googlesource.com/970082
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Aaron Gable <agable@chromium.org>

gclient.py

@@ -1736,6 +1736,10 @@ it or fix the checkout.
             # Delete the entry
             print('\n________ deleting \'%s\' in \'%s\'' % (
                 entry_fixed, self.root_dir))
+
+            # TOOO(thestig): Remove after debugging https://crbug.com/823586
+            print('\n________ because \'%s\' is not in: %s' % (
+                scm_root, full_entries))
             gclient_utils.rmtree(e_dir)
       # record the current list of entries for next time
       self._SaveEntries()

tests/gclient_smoketest.py

@@ -123,6 +123,11 @@ class GClientSmokeBase(fake_repos.FakeReposTestBase):
           re.match(r'_____ [^ ]+ : Attempting rebase onto [0-9a-f]+...', line)):
         continue
 
+      # TODO(thestig): Remove after debugging https://crbug.com/823586
+      match = re.match(r'^________ because \'.*\' is not in: \[.*\]$', line)
+      if match:
+        continue
+
       # Fail for any unrecognized lines that start with '__'.
       self.fail(line)
     return results