Add descriptions to the mini_installer test cases.

chrome/test/mini_installer/config/config.config

 {
   "states": [
     ["no_pv", ["chrome_user_no_pv.prop",
                "chrome_canary_no_pv.prop",
                "chrome_system_no_pv.prop"]],
     ["clean", ["chrome_user_not_installed.prop",
                "chrome_canary_not_installed.prop",
                "chrome_system_not_installed.prop",
                "chrome_user_not_inuse.prop",
                "chrome_canary_not_inuse.prop",
@@ skipping 72 matching lines @@
     ["uninstall_chrome_user",
      "python uninstall_chrome.py --chrome-long-name=\"$CHROME_LONG_NAME\""],
     ["uninstall_chrome_canary",
      "python uninstall_chrome.py --chrome-long-name=\"$CHROME_LONG_NAME_SXS\""],
     ["uninstall_chrome_system",
      "python uninstall_chrome.py --chrome-long-name=\"$CHROME_LONG_NAME\" --system-level"]
   ],
   "tests": [
     {
       "name": "RepairChromeStrandedBinaries",
+      "description": "Verifies that a multi-install update will repair Chrome if Chrome is missing from the Clients key yet appears to be actively used.",
       "traversal": [
         "no_pv",
         "install_chrome_user", "chrome_user_installed_not_inuse",
         "update_user_chrome_lastrun", "chrome_user_installed_not_inuse",
         "kill_user_chrome", "no_chrome_user",
         "update_multi_chrome_user", "chrome_user_installed_not_inuse",
         "uninstall_chrome_user", "clean"
       ]
     },
     {
       "name": "RemoveStrandedBinaries",
+      "description": "Verifies that a multi-install update will uninstall Chrome and the binaries if Chrome is missing from the Clients key and does not appear to be actively used.",
       "traversal": [
         "no_pv",
         "install_chrome_user", "chrome_user_installed_not_inuse",
         "update_user_chrome_lastrun", "chrome_user_installed_not_inuse",
         "delete_user_chrome_lastrun", "chrome_user_installed_not_inuse",
         "kill_user_chrome", "no_chrome_user",
         "update_multi_chrome_user", "clean"
       ]
     },
     {
       "name": "ChromeUserLevel",
+      "description": "Verifies that multi-install user-level Chrome can be installed and uninstalled.",
       "traversal": [
         "no_pv",
         "install_chrome_user", "chrome_user_installed_not_inuse",
         "uninstall_chrome_user", "clean"
       ]
     },
     {
       "name": "ChromeCanary",
+      "description": "Verifies that Chrome SxS can be installed and uninstalled.",
       "condition": "$SUPPORTS_SXS",
       "traversal": [
         "no_pv",
         "install_chrome_canary", "chrome_canary_installed_not_inuse",
         "uninstall_chrome_canary", "clean"
       ]
     },
     {
       "name": "ChromeSystemLevel",
+      "description": "Verifies that multi-install system-level Chrome can be installed and uninstalled.",
       "traversal": [
         "no_pv",
         "install_chrome_system", "chrome_system_installed_not_inuse",
         "uninstall_chrome_system", "clean"
       ]
     },
     {
       "name": "ChromeUserLevelWithCanary",
+      "description": "Verifies that multi-install user-level Chrome and Chrome SxS can be installed simultaneously.",
       "condition": "$SUPPORTS_SXS",
       "traversal": [
         "no_pv",
         "install_chrome_user", "chrome_user_installed_not_inuse",
         "install_chrome_canary", "chrome_user_and_canary_installed_not_inuse",
         "uninstall_chrome_user", "chrome_canary_installed_not_inuse",
         "uninstall_chrome_canary", "clean"
       ]
     }
   ]
 }