Add new trusty 64 slave to tryserver.infra.
Add new trusty 64 slave to tryserver.infra.

TBR=akuegel@chromium.org
BUG=403494,505640

Review URL: https://codereview.chromium.org/1296363002

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@296343 0039d316-1c4b-4281-b951-d872f2087c98

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