Manage PluginFactory plugin with a unique_ptr in CondDBESSource

[makortel]

This PR is preparatory work to change the PluginFactory to return a std::unique_ptr.

Tested in CMSSW_10_5_X_2019-01-23-1100, no changes expected.

[cmsbuild]

The code-checks are being triggered in jenkins.

[makortel]

@cmsbuild, please test

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-25816/8254

• This PR adds an extra 20KB to repository

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/32927/console Started: 2019/01/31 06:54

[cmsbuild]

A new Pull Request was created by @makortel (Matti Kortelainen) for master.

It involves the following packages:

CondCore/ESSources

@ggovi, @cmsbuild, @pohsun, @franzoni, @tocheng can you please review it and eventually sign? Thanks.
@mmusich, @tocheng this is something you requested to watch as well.
@davidlange6, @slava77, @fabiocos you are the release manager for this.

cms-bot commands are listed here

[cmsbuild]

+1
Tested at: 58509d0
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-25816/32927/summary.html

[cmsbuild]

Comparison job queued.

[ggovi]

+1

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-25816/32927/summary.html

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 32
• DQMHistoTests: Total histograms compared: 3097440
• DQMHistoTests: Total failures: 1
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3097242
• DQMHistoTests: Total skipped: 197
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 31 files compared)
• Checked 133 log files, 14 edm output root files, 32 DQM output files

[pohsun]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @davidlange6, @slava77, @smuzaffar, @fabiocos (and backports should be raised in the release meeting by the corresponding L2)

[fabiocos]

+1