mus: Add PointerWatcher for passively observing mouse and touch events

ash/mus/shell_delegate_mus.cc

Index: ash/mus/shell_delegate_mus.cc
diff --git a/ash/mus/shell_delegate_mus.cc b/ash/mus/shell_delegate_mus.cc
index 8aa0d332dff216baed317a920f1255d8113a37c3..901042c3c171c87f78916930dcee77c70ca3343c 100644
--- a/ash/mus/shell_delegate_mus.cc
+++ b/ash/mus/shell_delegate_mus.cc
@@ -9,6 +9,7 @@
 #include "ash/gpu_support_stub.h"
 #include "ash/media_delegate.h"
 #include "ash/mus/context_menu_mus.h"
+#include "ash/mus/pointer_watcher_delegate_mus.h"
 #include "ash/mus/shelf_delegate_mus.h"
 #include "ash/session/session_state_delegate.h"
 #include "ash/system/tray/default_system_tray_delegate.h"
@@ -225,6 +226,10 @@ MediaDelegate* ShellDelegateMus::CreateMediaDelegate() {
   return new MediaDelegateStub;
 }
 
+PointerWatcherDelegate* ShellDelegateMus::CreatePointerWatcherDelegate() {
+  return new PointerWatcherDelegateMus;
+}
+
 ui::MenuModel* ShellDelegateMus::CreateContextMenu(ash::Shelf* shelf,
                                                    const ShelfItem* item) {
   return new ContextMenuMus(shelf);