Enable feature SyncInstanceIDTokenTTL by default on ChromeOS and iOS

Bug: 1034915
Change-Id: I6fec4c0b51df3e3fc7e62c2ce1c5ac277584919d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2359138Reviewed-by: Rushan Suleymanov <rushans@google.com>
Commit-Queue: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798620}

components/invalidation/impl/invalidation_switches.cc

@@ -36,8 +36,8 @@ const base::Feature kTiclInvalidationsStartInvalidatorOnActiveHandler = {
 
 const base::Feature kSyncInstanceIDTokenTTL {
   "SyncInstanceIDTokenTTL",
-#if defined(OS_WIN) || defined(OS_MAC) || \
-    (defined(OS_LINUX) && !defined(OS_CHROMEOS))
+#if defined(OS_WIN) || defined(OS_MAC) || defined(OS_LINUX) || \
+    defined(OS_CHROMEOS) || defined(OS_IOS)
       base::FEATURE_ENABLED_BY_DEFAULT
 #else
       base::FEATURE_DISABLED_BY_DEFAULT