Introduce App Launcher for Windows.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index d1f6792fabbd90dd5c8b5e1a18fbfb6cd5a8967b..67ca22d12654c353c33ea435725c0631b25ba825 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -1184,6 +1184,9 @@ const char kServiceAccountLsid[]            = "service-account-lsid";
 // Sets a token in the token service, for testing.
 const char kSetToken[]                      = "set-token";
 
+// If true the app list will be shown.
+const char kShowAppList[]                   = "show-app-list";
+
 // Annotates forms with Autofill field type predictions.
 const char kShowAutofillTypePredictions[]   = "show-autofill-type-predictions";