Add the tokenizer.ondemand setting to Core for now.

Summary:
T2255 lists it as "???" and we don't have a "Misc" category and it seems silly
to make it for one option, so stick this in core for now.

Test Plan: Went to the setting page and saw the bool options.

Reviewers: epriestley, chad

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2255

Differential Revision: https://secure.phabricator.com/D4389

src/applications/config/option/PhabricatorCoreConfigOptions.php

@@ -80,6 +80,32 @@ final class PhabricatorCoreConfigOptions
             "non-standard locations."))
         ->addExample('/usr/local/bin', pht('Add One Path'))
         ->addExample("/usr/bin\n/usr/local/bin", pht('Add Multiple Paths')),
+       $this->newOption('tokenizer.ondemand', 'bool', false)
+        ->setBoolOptions(
+          array(
+            pht("Query on demand"),
+            pht("Query on page load"),
+          ))
+        ->setSummary(
+          pht("Query for tokenizer fields on demand."))
+        ->setDescription(
+          pht(
+            "Tokenizers are UI controls which let the user select other ".
+            "users, email addresses, project names, etc., by typing the ".
+            "first few letters and having the control autocomplete from a ".
+            "list. They can load their data in two ways: either in a big ".
+            "chunk up front, or as the user types. By default, the data is ".
+            "loaded in a big chunk. This is simpler and performs better for ".
+            "small datasets. However, if you have a very large number of ".
+            "users or projects, (in the ballpark of more than a thousand), ".
+            "loading all that data may become slow enough that it's ".
+            "worthwhile to query on demand instead. This makes the typeahead ".
+            "slightly less responsive but overall performance will be much ".
+            "better if you have a ton of stuff. You can figure out which ".
+            "setting is best for your install by changing this setting and ".
+            "then playing with a user tokenizer (like the user selectors in ".
+            "Maniphest or Differential) and seeing which setting loads ".
+            "faster and feels better.")),
     );
   }