Remove duplication between Mandoline and mojo_runner main functions.

mojo/runner/desktop/launcher_process.h

Index: mojo/runner/desktop/launcher_process.h
diff --git a/mojo/runner/desktop/launcher_process.h b/mojo/runner/desktop/launcher_process.h
index 9a7841a2d8748314c9972e463c25398a0bdd16b3..ec78f5bd5b722aaf0e969364339e265f89831c4f 100644
--- a/mojo/runner/desktop/launcher_process.h
+++ b/mojo/runner/desktop/launcher_process.h
@@ -5,11 +5,16 @@
 #ifndef MOJO_SHELL_LAUNCHER_PROCESS_H_
 #define MOJO_SHELL_LAUNCHER_PROCESS_H_
 
+#include "base/callback_forward.h"
+
+class GURL;
+
 namespace mojo {
 namespace runner {
 
 // Main method for the launcher process.
-int LauncherProcessMain(int argc, char** argv);
+// See commit in main_helper.h for explanation of the parameters.
+int LauncherProcessMain(const GURL& mojo_url, const base::Closure& callback);
 
 }  // namespace runner
 }  // namespace mojo