Mute devices when they're being used if the --mute-master option is given.

lib/cli.js

@@ -68,6 +68,8 @@ program
     , 'adb connect URL pattern'
     , String
     , '${publicIp}:${publicPort}')
+  .option('--mute-master'
+    , 'whether to mute master volume when devices are being used')
   .action(function() {
     var serials = cliutil.allUnknownArgs(arguments)
       , options = cliutil.lastArg(arguments)
@@ -107,7 +109,8 @@ program
         , '--screen-ws-url-pattern', options.screenWsUrlPattern
         , '--connect-url-pattern', options.connectUrlPattern
         , '--heartbeat-interval', options.heartbeatInterval
-        ])
+        ]
+        .concat(options.muteMaster ? ['--mute-master'] : []))
       }
     , endpoints: {
         sub: options.connectSub
@@ -167,6 +170,8 @@ program
     , 'heartbeat interval'
     , Number
     , 10000)
+  .option('--mute-master'
+    , 'whether to mute master volume when devices are being used')
   .action(function(serial, options) {
     if (!options.connectSub) {
       this.missingArgument('--connect-sub')
@@ -204,6 +209,7 @@ program
     , connectUrlPattern: options.connectUrlPattern
     , connectPort: options.connectPort
     , heartbeatInterval: options.heartbeatInterval
+    , muteMaster: options.muteMaster
     })
   })
 
@@ -911,6 +917,8 @@ program
   .option('--user-profile-url <url>'
     , 'URL to external user profile page'
     , String)
+  .option('--mute-master'
+    , 'whether to mute master volume when devices are being used')
   .action(function() {
     var log = logger.createLogger('cli:local')
       , args = arguments
@@ -976,6 +984,7 @@ program
           , '--adb-port', options.adbPort
           ]
           .concat(options.allowRemote ? ['--allow-remote'] : [])
+          .concat(options.muteMaster ? ['--mute-master'] : [])
           .concat(cliutil.allUnknownArgs(args)))
 
         // auth