Add descriptions to the mini_installer test cases.

BUG=none
R=gab@chromium.org

Review-Url: https://codereview.chromium.org/2158813002
Cr-Commit-Position: refs/heads/master@{#405994}

chrome/test/mini_installer/config/config.config

@@ -90,6 +90,7 @@
   "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",
@@ -101,6 +102,7 @@
     },
     {
       "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",
@@ -112,6 +114,7 @@
     },
     {
       "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",
@@ -120,6 +123,7 @@
     },
     {
       "name": "ChromeCanary",
+      "description": "Verifies that Chrome SxS can be installed and uninstalled.",
       "condition": "$SUPPORTS_SXS",
       "traversal": [
         "no_pv",
@@ -129,6 +133,7 @@
     },
     {
       "name": "ChromeSystemLevel",
+      "description": "Verifies that multi-install system-level Chrome can be installed and uninstalled.",
       "traversal": [
         "no_pv",
         "install_chrome_system", "chrome_system_installed_not_inuse",
@@ -137,6 +142,7 @@
     },
     {
       "name": "ChromeUserLevelWithCanary",
+      "description": "Verifies that multi-install user-level Chrome and Chrome SxS can be installed simultaneously.",
       "condition": "$SUPPORTS_SXS",
       "traversal": [
         "no_pv",