Refactors keyboard related code so mash can use a keyboard

ash/shell_init_params.h

Index: ash/shell_init_params.h
diff --git a/ash/shell_init_params.h b/ash/shell_init_params.h
index efa1511e132ff260e3e92d90eecb381c2988848b..68999e4d1f25b62cbfdd8dd91b634557eb0ca1d2 100644
--- a/ash/shell_init_params.h
+++ b/ash/shell_init_params.h
@@ -12,6 +12,8 @@
 #endif
 
 #include "ash/ash_export.h"
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
 
 namespace base {
 class SequencedWorkerPool;
@@ -23,6 +25,7 @@ class ContextFactory;
 
 namespace ash {
 
+class KeyboardUI;
 class ShellDelegate;
 
 struct ASH_EXPORT ShellInitParams {
@@ -34,6 +37,11 @@ struct ASH_EXPORT ShellInitParams {
   ui::ContextFactory* context_factory;
   base::SequencedWorkerPool* blocking_pool;
 
+  // True if running inside mus.
+  bool in_mus = false;
+
+  base::Callback<scoped_ptr<KeyboardUI>()> keyboard_factory;
+
 #if defined(OS_WIN)
   HWND remote_hwnd;
 #endif