Print more debugging info when rewinding a transaction.
Print more debugging info when rewinding a transaction.

BUG=chromium:346925
TEST=All unit tests.

Change-Id: I3b53472c609cf88ce0c83fb9f4e5734b7d72ab90
Reviewed-on: https://chromium-review.googlesource.com/187993
Reviewed-by: Yu-Ju Hong <52dc720c411f8e2156e608c1a8b894a917489667@chromium.org>
Commit-Queue: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Tested-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>

bpsinc-native/src_third_party_chromite,bpsinc-native/src_third_party_chromite,chadversary/chromiumos.chromite,chadversary/chromiumos.chromite,bpsinc-native/src_third_party_chromite