Set Chrome version/branch to 27.0.1438.8.

Change-Id: If698d6a079ac32d0f2648beec9811b0c971e7ed6
diff --git a/chromeos-base/chromeos-chrome/chromeos-chrome-27.0.1438.8_rc-r1.ebuild b/chromeos-base/chromeos-chrome/chromeos-chrome-27.0.1438.8.ebuild
similarity index 100%
rename from chromeos-base/chromeos-chrome/chromeos-chrome-27.0.1438.8_rc-r1.ebuild
rename to chromeos-base/chromeos-chrome/chromeos-chrome-27.0.1438.8.ebuild