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>
diff --git a/gclient.py b/gclient.py
index 21eeeb5..4867d26 100755
--- a/gclient.py
+++ b/gclient.py
@@ -1736,6 +1736,10 @@
             # 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()