The Chrome 20 patch provided a Chrome updater. This is beneficial because it works like other updaters (Java) where Chrome monitors which level you are at and puts the update in the user's hands.
For enterprise customers, using the silent command line to deploy the Chrome patch across their environment (using the chrome_installer.exe), this update produces an error. The work around is to download and install the GoogleChromeStandaloneEnterprise.msi. Per Google, this is the stable release.