aura-mus: Implement stacking in DesktopWindowTreeHostMus.

ui/views/mus/desktop_window_tree_host_mus_unittest.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 "ui/views/mus/desktop_window_tree_host_mus.h"
 
 #include "base/debug/stack_trace.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
 #include "ui/aura/client/cursor_client.h"
+#include "ui/aura/mus/in_flight_change.h"
 #include "ui/aura/window.h"
+#include "ui/views/mus/mus_client_test_observer.h"
+#include "ui/views/mus/test_utils.h"
 #include "ui/views/test/views_test_base.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_delegate.h"
 #include "ui/views/widget/widget_observer.h"
 
 namespace views {
 
 class DesktopWindowTreeHostMusTest : public ViewsTestBase,
                                      public WidgetObserver {
  public:
@@ skipping 72 matching lines @@
         aura::client::GetCursorClient(window->GetRootWindow());
     EXPECT_FALSE(cursor_client);
     window_->RemoveObserver(this);
     window_ = nullptr;
   }
 
   aura::Window* window_;
   DISALLOW_COPY_AND_ASSIGN(ExpectsNullCursorClientDuringTearDown);
 };
 
+class WaitForChangeCompletor : public test::MusClientTestObserver {
+ public:
+  WaitForChangeCompletor(aura::ChangeType type, bool success)
+      : type_(type), success_(success), received_(false) {
+    test::MusClientTestApi::SetChangeTestObserver(this);
+  }
+
+  ~WaitForChangeCompletor() override {
+    test::MusClientTestApi::SetChangeTestObserver(nullptr);
+  }
+
+  void Wait() {
+    if (!received_) {
+      quit_closure_ = run_loop_.QuitClosure();
+      run_loop_.Run();
+    }
+  }
+
+ private:
+  // test::MusClientTestObserver:
+  void OnChangeCompleted(aura::ChangeType type, bool success) override {
+    if (type == type_ && success == success_) {

[sky, 2017/01/20 16:36:10]

One potential problem with this pattern is that if there are already changes of
type in the queue this stops when the first one completes.

[Elliot Glaysher, 2017/01/20 22:31:02]

Moved this to ui/aura/test/mus/, and made it listen for the first change_id of
|type| after construction.

+      received_ = true;
+      if (quit_closure_)
+        quit_closure_.Run();
+    }
+  }
+
+  base::RunLoop run_loop_;
+  aura::ChangeType type_;
+  bool success_;
+  bool received_;
+  base::Closure quit_closure_;
+
+  DISALLOW_COPY_AND_ASSIGN(WaitForChangeCompletor);
+};
+
 TEST_F(DesktopWindowTreeHostMusTest, Visibility) {
   std::unique_ptr<Widget> widget(CreateWidget(nullptr));
   EXPECT_FALSE(widget->IsVisible());
   EXPECT_FALSE(widget->GetNativeView()->IsVisible());
   // It's important the parent is also hidden as this value is sent to the
   // server.
   EXPECT_FALSE(widget->GetNativeView()->parent()->IsVisible());
   widget->Show();
   EXPECT_TRUE(widget->IsVisible());
   EXPECT_TRUE(widget->GetNativeView()->IsVisible());
@@ skipping 25 matching lines @@
   widget->Show();
 
   std::unique_ptr<aura::Window> window(new aura::Window(nullptr));
   window->Init(ui::LAYER_SOLID_COLOR);
   ExpectsNullCursorClientDuringTearDown observer(window.get());
 
   widget->GetNativeWindow()->AddChild(window.release());
   widget.reset();
 }
 
+TEST_F(DesktopWindowTreeHostMusTest, StackAtTop) {
+  std::unique_ptr<Widget> widget1(CreateWidget(nullptr));
+  widget1->Show();
+
+  std::unique_ptr<Widget> widget2(CreateWidget(nullptr));
+  widget2->Show();
+
+  WaitForChangeCompletor waiter(aura::ChangeType::REORDER, true);
+  widget1->StackAtTop();
+  waiter.Wait();
+
+  // Other than the signal that our StackAtTop() succeeded, we don't have any
+  // pieces of public data that we can check. If we actually stopped waiting,
+  // count that as success.
+}
+
+TEST_F(DesktopWindowTreeHostMusTest, StackAtTopAlreadyOnTop) {
+  std::unique_ptr<Widget> widget1(CreateWidget(nullptr));
+  widget1->Show();
+
+  std::unique_ptr<Widget> widget2(CreateWidget(nullptr));
+  widget2->Show();
+
+  WaitForChangeCompletor waiter(aura::ChangeType::REORDER, true);
+  widget2->StackAtTop();
+  waiter.Wait();
+}
+
 }  // namespace views