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 7f671748797331e20da23db2d95a6116bb1c6c55)