Only pass in --shallow if we're on a system with 100Gb or less space
Only pass in --shallow if we're on a system with 100Gb or less space

Fix and reland of https://codereview.chromium.org/184393007/

The fix was:
1. s/path/cwd/, since path is already overloaded in this context as an alias for os.path
2. Move the disk space code path AFTER the hostname check, so this should in no way be
   able to activate on a non-botupdate machine.

BUG=339171
TESTS=Ran locally and passed. (Caviate: Local system is git 1.9, linux, and tonnes of disk space)
R=agable@chromium.org

Review URL: https://codereview.chromium.org/184103021

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@254897 0039d316-1c4b-4281-b951-d872f2087c98

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