Revert "Caches the display names in MultiDisplayManager."

This reverts commit ecb62a0bbbdda8ad7b73b786ee4c7e1e766e498a.

BUG=

Review URL: https://codereview.chromium.org/11363071

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@165790 0039d316-1c4b-4281-b951-d872f2087c98
4 files changed