Revert "Extract linux_chromium_clobber_rel_ng slaves to their own pool"
Revert "Extract linux_chromium_clobber_rel_ng slaves to their own pool"

This CL reverts https://codereview.chromium.org/1070783002.
It was a temporary solution and is not needed anymore.

BUG=475043

Review URL: https://codereview.chromium.org/1095263002

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@294913 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build