V8 Buildbot: Move back webkit win builder after slave was repaired.
V8 Buildbot: Move back webkit win builder after slave was repaired.

Also update the slave description.

Review URL: https://chromiumcodereview.appspot.com/22331007

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@216194 0039d316-1c4b-4281-b951-d872f2087c98

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