Enable setting configuration arguments for Mojo applications with mojo_shell

mojo/shell/switches.cc

Index: mojo/shell/switches.cc
diff --git a/mojo/shell/switches.cc b/mojo/shell/switches.cc
index b3f2ac3c2ea08929bbb37a4801c166af4abad31b..61a93e2ffd153605a7dbc53c0cc067204cd268cf 100644
--- a/mojo/shell/switches.cc
+++ b/mojo/shell/switches.cc
@@ -6,6 +6,10 @@
 
 namespace switches {
 
+// Specify configuration arguments for a Mojo application URL. For example:
+// --args-for='mojo://mojo_wget http://www.google.com'
+const char kArgsFor[] = "args-for";
+
 // Used to specify the type of child process (switch values from
 // |ChildProcess::Type|).
 const char kChildProcessType[] = "child-process-type";