Adds the ability to run chromeos with mus

chrome/app/chrome_main.cc

Index: chrome/app/chrome_main.cc
diff --git a/chrome/app/chrome_main.cc b/chrome/app/chrome_main.cc
index c5177ec1e5a4435d21c03a506a339ef8eb6004a0..2cc37702d9cd2f141e9a5a37cc81dc078c288f66 100644
--- a/chrome/app/chrome_main.cc
+++ b/chrome/app/chrome_main.cc
@@ -110,8 +110,10 @@ int ChromeMain(int argc, const char** argv) {
   version_info::Channel channel = chrome::GetChannel();
   if (channel == version_info::Channel::CANARY ||
       channel == version_info::Channel::UNKNOWN) {
-    if (command_line->HasSwitch(switches::kMash))
+    if (command_line->HasSwitch(switches::kMash) ||
+        command_line->HasSwitch(switches::kMus)) {
       return MashMain();
+    }
     WaitForMashDebuggerIfNecessary();
     if (service_manager::ServiceManagerIsRemote())
       params.env_mode = aura::Env::Mode::MUS;