Increase page size for SyncData DB from 4K to maximum supported 32K

sync/syncable/deferred_on_disk_directory_backing_store.cc

Index: sync/syncable/deferred_on_disk_directory_backing_store.cc
diff --git a/sync/syncable/deferred_on_disk_directory_backing_store.cc b/sync/syncable/deferred_on_disk_directory_backing_store.cc
index 0367e5bc6cccf3252ac91afb0d9ae12c2639675c..887b767c72d48a5b82c084cd33d9ff0e199d61c5 100644
--- a/sync/syncable/deferred_on_disk_directory_backing_store.cc
+++ b/sync/syncable/deferred_on_disk_directory_backing_store.cc
@@ -39,7 +39,11 @@ bool DeferredOnDiskDirectoryBackingStore::SaveChanges(
     // Reopen DB on disk.
     db_.reset(new sql::Connection);
     db_->set_exclusive_locking();
-    db_->set_page_size(4096);
+    if (IsSyncBackingDatabase32KEnabled()) {
+      db_->set_page_size(32768);
+    } else {
+      db_->set_page_size(4096);
+    }
     if (!db_->Open(backing_filepath_) || !InitializeTables())
       return false;