Delete deprecated DocumentRootImpl

Change-Id: I81dd58cc0564af4aa1c79670d5e836136762046a
Revert "Delete deprecated DocumentRootImpl"

This reverts commit 743ac98a34ad73af1c5026ea19a97cbf30f5bb0b.

Change-Id: I211890fef7c8020111539e4a894096d2af40706e
Merge remote-tracking branch 'upstream/master'