Add WindowPinType property on arua::Window

ui/aura/client/aura_constants.h

 // 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.
 
 #ifndef UI_AURA_CLIENT_AURA_CONSTANTS_H_
 #define UI_AURA_CLIENT_AURA_CONSTANTS_H_
 
 #include <string>
 
 #include "base/strings/string16.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/aura/aura_export.h"
 #include "ui/aura/window.h"
 #include "ui/base/ui_base_types.h"
 
 namespace ui {
 namespace mojom {
 enum class WindowType;
 }
 }
 
 namespace aura {
 namespace client {
 
+enum class WindowPinType {
+  NONE,
+  PINNED,
+  TRUSTED_PINNED,
+};
+
 enum class WindowEmbedType {
   NONE,
   EMBED_IN_OWNER,
   TOP_LEVEL_IN_WM,
 };
 
 // Alphabetical sort.
 
 // A property key to store whether accessibility focus falls back to widget or
 // not.
@@ skipping 82 matching lines @@
 // view is the tab strip for tabbed browser windows, the toolbar for popups,
 // the web contents for app windows and varies for fullscreen windows.
 AURA_EXPORT extern const WindowProperty<int>* const kTopViewInset;
 
 // The color of the window header.
 AURA_EXPORT extern const WindowProperty<SkColor>* const kTopViewColor;
 
 // A property key to store the window icon, typically 16x16 for title bars.
 AURA_EXPORT extern const WindowProperty<gfx::ImageSkia*>* const kWindowIconKey;
 
+// A property key to store aura::client::WindowPinType for a window.
+// When setting this property to PINNED or TRUSTED_PINNED, the window manager
+// will try to fullscreen the window and pin it on the top of the screen. If the
+// window manager failed to do it, the property will be restored to NONE. When
+// setting this property to NONE, the window manager will restore the window.
+AURA_EXPORT extern const WindowProperty<WindowPinType>* const kWindowPinTypeKey;
+
 // Indicates the type of embedding within the given window.
 AURA_EXPORT extern const WindowProperty<WindowEmbedType>* const kEmbedType;
 
 AURA_EXPORT extern const WindowProperty<ui::mojom::WindowType>* const
     kWindowTypeKey;
 
 // Alphabetical sort.
 
 }  // namespace client
 }  // namespace aura
 
 #endif  // UI_AURA_CLIENT_AURA_CONSTANTS_H_