DO NOT MERGE: fix for the XPath nodeTab use-after-free bug from nmehta@ see https://bugs.chromium.org/p/chromium/issues/detail?id=705445 Bug: 36809819 Change-Id: I4832550032669a8e921bd46068281d9daf594ae1 (cherry picked from commit cda50e74e81cf20ba01622e087c20c0764c85595)