tryserver.chromium.linux: Add more Linux ccompute.
tryserver.chromium.linux: Add more Linux ccompute.

Add 'linux_chromium_chromeos_ozone_rel_ng' to the active tryserver Linux
builder pool.

Add ccompute slave7{79..98}-c4 to the Linux slave pool.

BUG=chromium:440882
TEST=local
  - Started master locally; verify that the slaves are mapped.

Review URL: https://codereview.chromium.org/1003813005

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@294453 0039d316-1c4b-4281-b951-d872f2087c98

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