dpkg-dev was added to third_party in CL:
https://codereview.chromium.org/2411423002/
The version of the utility to calculate Debian dependencies, dpkg-shlibdeps, was too old on Precise to support the feature we needed for using the sysroot to calculate dependencies (specifically, the "-l" option was needed). This meant we needed to temporarily bundle a newer version dpkg-dev to get this working on Precise.
Trusty has a newer version of dpkg-dev with the necessary feature, so dpkg-dev should be removed once the builders are entirely switch off of Precise.
This can be done by reverting the above CL and applying ps40001.
Comment 1 by bugdroid1@chromium.org
, Jan 27 2017