Corrects NativeWidgetAura state model to not minimize on every restore

ui/views/widget/native_widget_aura_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/widget/native_widget_aura.h"
 
 #include <memory>
 
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/env.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/test/aura_test_base.h"
 #include "ui/aura/window.h"
+#include "ui/aura/window_observer.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/events/event.h"
 #include "ui/events/event_utils.h"
 #include "ui/gfx/screen.h"
 #include "ui/views/layout/fill_layout.h"
 #include "ui/views/test/widget_test.h"
 #include "ui/views/widget/root_view.h"
 #include "ui/views/widget/widget_delegate.h"
 #include "ui/wm/core/base_focus_rules.h"
 #include "ui/wm/core/default_activation_client.h"
@@ skipping 115 matching lines @@
   params.show_state = ui::SHOW_STATE_MINIMIZED;
   params.bounds.SetRect(0, 0, 1024, 800);
   std::unique_ptr<Widget> widget(new Widget());
   widget->Init(params);
   widget->Show();
 
   EXPECT_TRUE(widget->IsMinimized());
   widget->CloseNow();
 }
 
+// A WindowObserver that counts kShowStateKey property changes.
+class TestWindowObserver : public aura::WindowObserver {
+ public:
+  TestWindowObserver(gfx::NativeWindow window) : window_(window) {

[sky, 2016/04/25 15:01:18]

explicit

[varkha, 2016/04/25 15:56:57]

Done.

+    window_->AddObserver(this);
+  }
+  ~TestWindowObserver() override {
+    window_->RemoveObserver(this);
+  }
+
+  // aura::WindowObserver:
+  void OnWindowPropertyChanged(aura::Window* window,
+                               const void* key,
+                               intptr_t old) override {
+    if (key != aura::client::kShowStateKey)
+      return;
+    count_++;
+    state_ = window_->GetProperty(aura::client::kShowStateKey);
+  }
+
+  int count() const { return count_; }
+  ui::WindowShowState state() const { return state_; }
+  void Reset() { count_ = 0; }
+
+ private:
+  gfx::NativeWindow window_;
+  int count_ = 0;
+  ui::WindowShowState state_ = ui::WindowShowState::SHOW_STATE_DEFAULT;
+
+ DISALLOW_COPY_AND_ASSIGN(TestWindowObserver);
+};
+
+// Tests that window transitions from normal to minimized and back do not
+// involve extra show state transitions.
+TEST_F(NativeWidgetAuraTest, ToggleState) {
+  Widget::InitParams params(Widget::InitParams::TYPE_WINDOW);
+  params.ownership = Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
+  params.parent = NULL;

[sky, 2016/04/25 15:01:18]

nullptr

[varkha, 2016/04/25 15:56:57]

Done. Here and elsewhere in this file.

+  params.context = root_window();
+  params.show_state = ui::SHOW_STATE_NORMAL;
+  params.bounds.SetRect(0, 0, 1024, 800);
+  std::unique_ptr<Widget> widget(new Widget());

[sky, 2016/04/25 15:01:18]

nit: no need for a unique_ptr here, declare widget on the stack.

[varkha, 2016/04/25 15:56:57]

Done.

+  widget->Init(params);
+  std::unique_ptr<TestWindowObserver> observer(
+      new TestWindowObserver(widget->GetNativeWindow()));
+  widget->Show();
+  EXPECT_FALSE(widget->IsMinimized());
+  EXPECT_EQ(0, observer->count());
+  EXPECT_EQ(ui::WindowShowState::SHOW_STATE_DEFAULT, observer->state());
+
+  widget->Minimize();
+  EXPECT_TRUE(widget->IsMinimized());
+  EXPECT_EQ(1, observer->count());
+  EXPECT_EQ(ui::WindowShowState::SHOW_STATE_MINIMIZED, observer->state());
+  observer->Reset();
+
+  widget->Show();
+  widget->Restore();
+  EXPECT_EQ(1, observer->count());
+  EXPECT_EQ(ui::WindowShowState::SHOW_STATE_NORMAL, observer->state());
+
+  observer.reset();
+  EXPECT_FALSE(widget->IsMinimized());
+  widget->CloseNow();
+}
+
 class TestLayoutManagerBase : public aura::LayoutManager {
  public:
   TestLayoutManagerBase() {}
   ~TestLayoutManagerBase() override {}
 
   // aura::LayoutManager:
   void OnWindowResized() override {}
   void OnWindowAddedToLayout(aura::Window* child) override {}
   void OnWillRemoveWindowFromLayout(aura::Window* child) override {}
   void OnWindowRemovedFromLayout(aura::Window* child) override {}
@@ skipping 367 matching lines @@
   EXPECT_FALSE(delegate.view()->HasFocus());
 
   test_focus_rules()->set_can_activate(true);
   views::test::TestInitialFocusWidgetDelegate delegate2(root_window());
   delegate2.GetWidget()->Show();
   EXPECT_TRUE(delegate2.view()->HasFocus());
 }
 
 }  // namespace
 }  // namespace views