AppListController refactoring part 1: AppListShower implementation.

ui/app_list/shower/app_list_shower.h

Index: ui/app_list/shower/app_list_shower.h
diff --git a/ui/app_list/shower/app_list_shower.h b/ui/app_list/shower/app_list_shower.h
new file mode 100644
index 0000000000000000000000000000000000000000..ac94a4a06cadab5a9a1d5fac82811be866f9191b
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+++ b/ui/app_list/shower/app_list_shower.h
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+// 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.
+
+#ifndef UI_APP_LIST_SHOWER_APP_LIST_SHOWER_H_
+#define UI_APP_LIST_SHOWER_APP_LIST_SHOWER_H_
+
+#include "ui/app_list/shower/app_list_shower_export.h"
+
+namespace aura {
+class Window;
+}
+
+namespace app_list {
+
+// Interface for showing and hiding the app list.
+class APP_LIST_SHOWER_EXPORT AppListShower {
+ public:
+  virtual ~AppListShower() {}
+
+  // Show/hide app list window. The |window| is used to deterime in
+  // which display (in which the |window| exists) the app list should
+  // be shown.
+  virtual void Show(aura::Window* window) = 0;
+
+  // Invoked to dismiss app list. This may leave the view open but hidden from
+  // the user.
+  virtual void Dismiss() = 0;
+
+  // Whether the app list's aura::Window is currently visible.
+  virtual bool IsVisible() const = 0;
+
+  // Returns target visibility. This may differ from IsVisible() if a
+  // visibility transition is in progress.
+  virtual bool GetTargetVisibility() const = 0;
+};
+
+}  // namespace app_list
+
+#endif  // UI_APP_LIST_SHOWER_APP_LIST_SHOWER_H_