Removed mac support in master-common-rules.mk
Removed mac support in master-common-rules.mk

Master processes don't run on Mac OS anyway.

BUG=

Review URL: https://codereview.chromium.org/1005393005

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@294580 0039d316-1c4b-4281-b951-d872f2087c98

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