am e1c1ac8b: Merge change 3869 into donut

Merge commit 'e1c1ac8b0ea535e334b7f072aaaa98d14dcb8b81'

* commit 'e1c1ac8b0ea535e334b7f072aaaa98d14dcb8b81':
  SDK Updater: implement tree check callback on remote page.