views/mus: Have explicit ownership of views::WindowManagerConnection.

mash/task_viewer/task_viewer.h

Index: mash/task_viewer/task_viewer.h
diff --git a/mash/task_viewer/task_viewer.h b/mash/task_viewer/task_viewer.h
index 372c29398efe18d625a7ef10f954de0fb51668a3..7f8f9110d1e78c39ea4c0b50a9dc3f7f6ec098d3 100644
--- a/mash/task_viewer/task_viewer.h
+++ b/mash/task_viewer/task_viewer.h
@@ -18,6 +18,7 @@
 namespace views {
 class AuraInit;
 class Widget;
+class WindowManagerConnection;
 }
 
 namespace mash {
@@ -52,6 +53,7 @@ class TaskViewer : public shell::ShellClient,
 
   mojo::TracingImpl tracing_;
   std::unique_ptr<views::AuraInit> aura_init_;
+  std::unique_ptr<views::WindowManagerConnection> window_manager_connection_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskViewer);
 };