Used list::splice() for clock::tick().
Used list::splice() for clock::tick().

Review: https://reviews.apache.org/r/43462/

chhsia0/mesos,neilconway/mesos,yuquanshan/customizedMesos,reneploetz/mesos,verizonlabs/mesos,reneploetz/mesos,andschwa/mesos,kaysoky/mesos,abudnik/mesos,neilconway/mesos,chhsia0/mesos,craimbert/mesos,asamerh4/mesos,reneploetz/mesos,zmalik/mesos,verizonlabs/mesos,neilconway/mesos,verizonlabs/mesos,yuquanshan/customizedMesos,abudnik/mesos,Aman-Jain-14/customizedMesos,kaysoky/mesos,chhsia0/mesos,craimbert/mesos,chhsia0/mesos,reneploetz/mesos,asamerh4/mesos,Gilbert88/mesos,dforsyth/mesos,Aman-Jain-14/customizedMesos,zmalik/mesos,verizonlabs/mesos,Aman-Jain-14/customizedMesos,gsantovena/mesos,abudnik/mesos,asamerh4/mesos,gsantovena/mesos,Gilbert88/mesos,Gilbert88/mesos,jpeach/mesos,asamerh4/mesos,zmalik/mesos,kaysoky/mesos,Aman-Jain-14/customizedMesos,kaysoky/mesos,kaysoky/mesos,dforsyth/mesos,andschwa/mesos,dforsyth/mesos,reneploetz/mesos,craimbert/mesos,Aman-Jain-14/customizedMesos,abudnik/mesos,Gilbert88/mesos,yuquanshan/customizedMesos,chhsia0/mesos,Gilbert88/mesos,verizonlabs/mesos,jpeach/mesos,chhsia0/mesos,dforsyth/mesos,andschwa/mesos,craimbert/mesos,gsantovena/mesos,neilconway/mesos,andschwa/mesos,zmalik/mesos,verizonlabs/mesos,yuquanshan/customizedMesos,yuquanshan/customizedMesos,Aman-Jain-14/customizedMesos,jpeach/mesos,gsantovena/mesos,yuquanshan/customizedMesos,abudnik/mesos,Gilbert88/mesos,dforsyth/mesos,gsantovena/mesos,jpeach/mesos,zmalik/mesos,Aman-Jain-14/customizedMesos,craimbert/mesos,reneploetz/mesos,andschwa/mesos,craimbert/mesos,asamerh4/mesos,dforsyth/mesos,dforsyth/mesos,kaysoky/mesos,abudnik/mesos,chhsia0/mesos,reneploetz/mesos,gsantovena/mesos,Gilbert88/mesos,jpeach/mesos,asamerh4/mesos,abudnik/mesos,andschwa/mesos,jpeach/mesos,kaysoky/mesos,asamerh4/mesos,gsantovena/mesos,andschwa/mesos,neilconway/mesos,craimbert/mesos,yuquanshan/customizedMesos,jpeach/mesos,zmalik/mesos,zmalik/mesos,neilconway/mesos,verizonlabs/mesos,neilconway/mesos