[Sync] Add client-side plumbing for server control of sessions commit delay

chrome/browser/sync/engine/syncer.cc

Index: chrome/browser/sync/engine/syncer.cc
diff --git a/chrome/browser/sync/engine/syncer.cc b/chrome/browser/sync/engine/syncer.cc
index fae03fa1787d343373a5537f1a776b1352075129..236daf8700b6b0c94ce5f6d2b4c744f80596d8f2 100644
--- a/chrome/browser/sync/engine/syncer.cc
+++ b/chrome/browser/sync/engine/syncer.cc
@@ -312,6 +312,11 @@ void Syncer::ProcessClientCommand(sessions::SyncSession* session) {
     session->delegate()->OnReceivedShortPollIntervalUpdate(
         TimeDelta::FromSeconds(command.set_sync_poll_interval()));
   }
+
+  if (command.has_sessions_commit_delay_seconds()) {
+    session->delegate()->OnReceivedSessionsCommitDelay(
+        TimeDelta::FromSeconds(command.sessions_commit_delay_seconds()));
+  }
 }
 
 void CopyServerFields(syncable::Entry* src, syncable::MutableEntry* dest) {