Re-write many calls to WrapUnique() with MakeUnique()

ash/host/ash_window_tree_host_unified.cc

Index: ash/host/ash_window_tree_host_unified.cc
diff --git a/ash/host/ash_window_tree_host_unified.cc b/ash/host/ash_window_tree_host_unified.cc
index 4e281f99e55c4239893adba6397f41451d338f85..550a13d6098a5b9f8e18eeb0550408d8db1f5e2d 100644
--- a/ash/host/ash_window_tree_host_unified.cc
+++ b/ash/host/ash_window_tree_host_unified.cc
@@ -71,7 +71,7 @@ void AshWindowTreeHostUnified::RegisterMirroringHost(
     AshWindowTreeHost* mirroring_ash_host) {
   aura::Window* src_root = mirroring_ash_host->AsWindowTreeHost()->window();
   src_root->SetEventTargeter(
-      base::WrapUnique(new UnifiedEventTargeter(src_root, window())));
+      base::MakeUnique<UnifiedEventTargeter>(src_root, window()));
   DCHECK(std::find(mirroring_hosts_.begin(), mirroring_hosts_.end(),
                    mirroring_ash_host) == mirroring_hosts_.end());
   mirroring_hosts_.push_back(mirroring_ash_host);