Adds ability for chrome to behave as mojo_runner

mojo/shell/background/background_shell.h

Index: mojo/shell/background/background_shell.h
diff --git a/mojo/shell/background/background_shell.h b/mojo/shell/background/background_shell.h
index d1e9c412438094b186bfdcc445873b0759086655..e04d28291f6b72bbbb4b5f64c50be448a6b51e1b 100644
--- a/mojo/shell/background/background_shell.h
+++ b/mojo/shell/background/background_shell.h
@@ -17,7 +17,7 @@ class GURL;
 namespace mojo {
 namespace shell {
 
-struct CommandLineSwitch;
+class NativeRunnerDelegate;
 
 // BackgroundShell starts up the mojo shell on a background thread, and
 // destroys the thread in the destructor. Once created use CreateApplication()
@@ -28,9 +28,8 @@ class BackgroundShell {
   BackgroundShell();
   ~BackgroundShell();
 
-  // Starts the background shell. |command_line_switches| are additional
-  // switches applied to any processes spawned by this call.
-  void Init(const std::vector<CommandLineSwitch>& command_line_switches);
+  // Starts the background shell.
+  void Init(NativeRunnerDelegate* native_runner_delegate);
 
   // Obtains an InterfaceRequest for the specified url.
   InterfaceRequest<mojom::ShellClient> CreateShellClientRequest(