Provide an API to the example window manager app that supports closing a window.

mojo/services/public/cpp/view_manager/lib/view.cc

Index: mojo/services/public/cpp/view_manager/lib/view.cc
diff --git a/mojo/services/public/cpp/view_manager/lib/view.cc b/mojo/services/public/cpp/view_manager/lib/view.cc
index be4397ba4740ff77534db358048c213143dfcada..0e2738f22dc06c2f7f910e9289208468bbe0a0a9 100644
--- a/mojo/services/public/cpp/view_manager/lib/view.cc
+++ b/mojo/services/public/cpp/view_manager/lib/view.cc
@@ -79,9 +79,13 @@ View::View()
       manager_(NULL) {}
 
 View::~View() {
-  ScopedDestructionNotifier notifier(this);
-  if (manager_)
-    ViewManagerPrivate(manager_).RemoveView(id_);
+  {
+    // TODO(beng): I'm not sure I like these scoped destruction notifiers.
+    //             When they fall out of scope |this| is toast.
+    ScopedDestructionNotifier notifier(this);
+    if (manager_)
+      ViewManagerPrivate(manager_).RemoveView(id_);
+  }
 }
 
 void View::LocalDestroy() {