Converts mash to use Shell

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 58495908a60b9283a8bf4921f600ee200ff6ae2b..3a2136b4b348268c2738f49588f93b241f8cf581 100644
--- a/ash/shell_init_params.h
+++ b/ash/shell_init_params.h
@@ -7,6 +7,10 @@
 
 #include "ash/ash_export.h"
 
+namespace aura {
+class WindowTreeHostMus;
+}
+
 namespace base {
 class SequencedWorkerPool;
 }
@@ -20,6 +24,11 @@ namespace ash {
 class ShellDelegate;
 
 struct ASH_EXPORT ShellInitParams {
+  // Shell takes ownership of |wm_shell|.
+  // TODO(sky): temporary, will eventually go away.
+  WmShell* wm_shell = nullptr;
+  // Shell takes ownership of |primary_window_tree_host|.
+  aura::WindowTreeHostMus* primary_window_tree_host = nullptr;

[James Cook, 2017/01/18 01:00:25]

Maybe mention in the comment that this is not used on classic ash.

[sky, 2017/01/18 04:00:08]

Done.

   ShellDelegate* delegate = nullptr;
   ui::ContextFactory* context_factory = nullptr;
   ui::ContextFactoryPrivate* context_factory_private = nullptr;