mus: Change PointerWatcher to observe all pointer events, with moves optional.

services/navigation/view_impl.cc

Index: services/navigation/view_impl.cc
diff --git a/services/navigation/view_impl.cc b/services/navigation/view_impl.cc
index 6037e8fbcf87a44e5e5fe4b347addf114ef095dc..a6451d12f77e5c2999bee48fcb55c3a31595fd7e 100644
--- a/services/navigation/view_impl.cc
+++ b/services/navigation/view_impl.cc
@@ -280,7 +280,8 @@ void ViewImpl::OnEmbed(ui::Window* root) {
 }
 
 void ViewImpl::OnDidDestroyClient(ui::WindowTreeClient* client) {}
-void ViewImpl::OnEventObserved(const ui::Event& event, ui::Window* target) {}
+void ViewImpl::OnPointerEventObserved(const ui::PointerEvent& event,
+                                      ui::Window* target) {}
 
 views::View* ViewImpl::GetContentsView() {
   return web_view_;