Do not switch to target Xcode version if it's already selected
Do not switch to target Xcode version if it's already selected

BUG=462104
R=dba@google.com

Review URL: https://codereview.chromium.org/1039503002

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@294583 0039d316-1c4b-4281-b951-d872f2087c98

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