MacViews: Be robust against Views manipulating Layers during Widget::Close().

ui/views/view_unittest.cc

 // Copyright (c) 2012 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 "ui/views/view.h"
 
 #include <stddef.h>
 
 #include <map>
 #include <memory>
@@ skipping 4600 matching lines @@
   params.bounds = gfx::Rect(50, 50, 350, 350);
   widget.Init(params);
 
   AddViewWithChildLayer(widget.GetRootView());
   ViewThatAddsViewInOnNativeThemeChanged* v =
       new ViewThatAddsViewInOnNativeThemeChanged;
   widget.GetRootView()->AddChildView(v);
   EXPECT_TRUE(v->on_native_theme_changed_called());
 }
 
+// A View that removes its Layer when hidden.
+class NoLayerWhenHiddenView : public View {
+ public:
+  NoLayerWhenHiddenView() {
+    SetPaintToLayer(true);
+    set_owned_by_client();
+    SetBounds(0, 0, 100, 100);
+  }
+
+  bool was_hidden() const { return was_hidden_; }
+
+  // View:
+  void VisibilityChanged(View* starting_from, bool is_visible) override {
+    if (!is_visible) {
+      was_hidden_ = true;
+      SetPaintToLayer(false);
+    }
+  }
+
+ private:
+  bool was_hidden_ = false;
+
+  DISALLOW_COPY_AND_ASSIGN(NoLayerWhenHiddenView);
+};
+
+// Test that Views can safely manipulate Layers during Widget closure.
+TEST_F(ViewTest, DestroyLayerInClose) {
+  NoLayerWhenHiddenView view;
+  Widget* widget = new Widget;
+  Widget::InitParams params = CreateParams(Widget::InitParams::TYPE_WINDOW);
+  widget->Init(params);
+  widget->SetBounds(gfx::Rect(0, 0, 100, 100));
+  widget->GetContentsView()->AddChildView(&view);
+  widget->Show();
+
+  EXPECT_TRUE(view.layer());
+  EXPECT_TRUE(view.GetWidget());
+  EXPECT_FALSE(view.was_hidden());
+
+  widget->Close();
+  if (IsAuraMusClient()) {
+    // Mus on Ozone doesn't send the visibility change during Close().
+    // See http://crbug.com/674003.
+    EXPECT_TRUE(view.layer());
+    EXPECT_FALSE(view.was_hidden());
+  } else {
+    EXPECT_FALSE(view.layer());
+    // Ensure the layer went away via VisibilityChanged().
+    EXPECT_TRUE(view.was_hidden());
+  }
+
+  // Not removed from Widget until Close() completes.
+  EXPECT_TRUE(view.GetWidget());
+  base::RunLoop().RunUntilIdle();  // Let the Close() complete.
+  EXPECT_FALSE(view.GetWidget());
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Observer tests.
 ////////////////////////////////////////////////////////////////////////////////
 
 class ViewObserverTest : public ViewTest, public ViewObserver {
  public:
   ViewObserverTest()
       : child_view_added_times_(0),
         child_view_removed_times_(0),
         child_view_added_(nullptr),
@@ skipping 139 matching lines @@
   std::unique_ptr<View> view = NewView();
   std::unique_ptr<View> child_view = NewView();
   std::unique_ptr<View> child_view2 = NewView();
   view->AddChildView(child_view.get());
   view->AddChildView(child_view2.get());
   view->ReorderChildView(child_view2.get(), 0);
   EXPECT_EQ(child_view2.get(), view_reordered());
 }
 
 }  // namespace views