mus: Add PointerWatcher for passively observing mouse and touch events

ash/test/test_shell_delegate.cc

Index: ash/test/test_shell_delegate.cc
diff --git a/ash/test/test_shell_delegate.cc b/ash/test/test_shell_delegate.cc
index 1566a5892bbd68a483fc60d87a2ebcc634680dae..94f79a92ea1de175714a6de744d84a45daac4dc8 100644
--- a/ash/test/test_shell_delegate.cc
+++ b/ash/test/test_shell_delegate.cc
@@ -13,6 +13,7 @@
 #include "ash/gpu_support_stub.h"
 #include "ash/media_delegate.h"
 #include "ash/new_window_delegate.h"
+#include "ash/pointer_watcher_delegate_aura.h"
 #include "ash/session/session_state_delegate.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
@@ -203,6 +204,11 @@ MediaDelegate* TestShellDelegate::CreateMediaDelegate() {
   return new MediaDelegateImpl;
 }
 
+std::unique_ptr<PointerWatcherDelegate>
+TestShellDelegate::CreatePointerWatcherDelegate() {
+  return base::WrapUnique(new PointerWatcherDelegateAura);
+}
+
 ui::MenuModel* TestShellDelegate::CreateContextMenu(
     ash::Shelf* shelf,
     const ash::ShelfItem* item) {