Implement cycle window forward/backward by keyboard shortcuts.

ui/aura_shell/shell_unittest.cc

Index: ui/aura_shell/shell_unittest.cc
diff --git a/ui/aura_shell/shell_unittest.cc b/ui/aura_shell/shell_unittest.cc
index 1be14e77a3291ff9ad86105700ca321cc353cd67..f00a3dfac2e47b4f4a1adec6995183bbdeb75244 100644
--- a/ui/aura_shell/shell_unittest.cc
+++ b/ui/aura_shell/shell_unittest.cc
@@ -203,5 +203,49 @@ TEST_F(ShellTest, CreateLockScreenModalWindow) {
   widget->Close();
 }
 
+TEST_F(ShellTest, IsScreenLocked) {
+  views::Widget::InitParams widget_params(
+      views::Widget::InitParams::TYPE_WINDOW);
+
+  // A normal window does not lock the screen.
+  views::Widget* widget = CreateTestWindow(widget_params);
+  widget->Show();
+  EXPECT_FALSE(Shell::GetInstance()->IsScreenLocked());
+  widget->Hide();
+  EXPECT_FALSE(Shell::GetInstance()->IsScreenLocked());
+
+  // A modal window with a normal window as parent does not locks the screen.
+  views::Widget* modal_widget = views::Widget::CreateWindowWithParent(
+      new ModalWindow(), widget->GetNativeView());
+  modal_widget->Show();
+  EXPECT_FALSE(Shell::GetInstance()->IsScreenLocked());
+  modal_widget->Close();
+  EXPECT_FALSE(Shell::GetInstance()->IsScreenLocked());
+  widget->Close();
+
+  // A lock screen window locks the screen.
+  views::Widget* lock_widget = CreateTestWindow(widget_params);
+  aura_shell::Shell::GetInstance()->GetContainer(
+      aura_shell::internal::kShellWindowId_LockScreenContainer)->
+      AddChild(lock_widget->GetNativeView());
+  lock_widget->Show();
+  EXPECT_TRUE(Shell::GetInstance()->IsScreenLocked());
+  lock_widget->Hide();
+  EXPECT_FALSE(Shell::GetInstance()->IsScreenLocked());
+
+  // A modal window with a lock window as parent does not lock the screen. The
+  // screen is locked only when a lock windown is visible.
+  views::Widget* lock_modal_widget = views::Widget::CreateWindowWithParent(
+      new ModalWindow(), lock_widget->GetNativeView());
+  lock_modal_widget->Show();
+  EXPECT_FALSE(Shell::GetInstance()->IsScreenLocked());
+  lock_widget->Show();
+  EXPECT_TRUE(Shell::GetInstance()->IsScreenLocked());
+  lock_modal_widget->Close();
+  EXPECT_TRUE(Shell::GetInstance()->IsScreenLocked());
+  lock_widget->Close();
+  EXPECT_FALSE(Shell::GetInstance()->IsScreenLocked());
+}
+
 }  // namespace test
 }  // namespace aura_shell