exo: Add notification surface to manager after commit

components/exo/notification_surface.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/exo/notification_surface.h"
 
 #include "components/exo/notification_surface_manager.h"
 #include "components/exo/surface.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
@@ skipping 67 matching lines @@
       notification_id_(notification_id),
       window_(new aura::Window(new CustomWindowDelegate(surface))) {
   surface_->SetSurfaceDelegate(this);
   surface_->AddSurfaceObserver(this);
 
   window_->SetType(ui::wm::WINDOW_TYPE_CONTROL);
   window_->SetName("ExoNotificationSurface");
   window_->Init(ui::LAYER_NOT_DRAWN);
   window_->set_owned_by_parent(false);
 
-  // TODO(xiyuan): Fix after Surface no longer has an auar::Window.
+  // TODO(xiyuan): Fix after Surface no longer has an aura::Window.
   window_->AddChild(surface_->window());
   surface_->window()->Show();
-
-  manager_->AddSurface(this);
 }
 
 NotificationSurface::~NotificationSurface() {
   if (surface_) {
     surface_->SetSurfaceDelegate(nullptr);
     surface_->RemoveSurfaceObserver(this);
   }
-  manager_->RemoveSurface(this);
+  if (added_to_manager_)
+    manager_->RemoveSurface(this);
 }
 
 gfx::Size NotificationSurface::GetSize() const {
   return surface_->content_size();
 }
 
 void NotificationSurface::OnSurfaceCommit() {
   surface_->CheckIfSurfaceHierarchyNeedsCommitToNewSurfaces();
   surface_->CommitSurfaceHierarchy();
 
   gfx::Rect bounds = window_->bounds();
   if (bounds.size() != surface_->content_size()) {
     bounds.set_size(surface_->content_size());
     window_->SetBounds(bounds);
   }
+
+  // Defer AddSurface until there are contents to show.
+  if (!added_to_manager_ && !surface_->content_size().IsEmpty()) {
+    added_to_manager_ = true;
+    manager_->AddSurface(this);
+  }
 }
 
 bool NotificationSurface::IsSurfaceSynchronized() const {
   return false;
 }
 
 void NotificationSurface::OnSurfaceDestroying(Surface* surface) {
   window_.reset();
   surface->RemoveSurfaceObserver(this);
   surface_ = nullptr;
 }
 
 }  // namespace exo