Add workspace to desktop

ui/aura_shell/default_container_event_filter.h

Index: ui/aura_shell/default_container_event_filter.h
diff --git a/ui/aura_shell/default_container_event_filter.h b/ui/aura_shell/default_container_event_filter.h
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+// Copyright (c) 2011 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_SHELL_DEFAULT_CONTAINER_EVENT_FILTER_H_
+#define UI_AURA_SHELL_DEFAULT_CONTAINER_EVENT_FILTER_H_
+#pragma once
+
+#include "ui/aura/toplevel_window_event_filter.h"
+
+namespace aura_shell {
+namespace internal {
+
+class DefaultContainerEventFilter : public aura::ToplevelWindowEventFilter {
+ public:
+  explicit DefaultContainerEventFilter(aura::Window* owner);
+  virtual ~DefaultContainerEventFilter();
+
+  // Overridden from aura::ToplevelWindowEventFilter:
+  virtual bool OnMouseEvent(aura::Window* target,
+                            aura::MouseEvent* event) OVERRIDE;
+
+ private:
+  enum DragState {
+    DRAG_NONE,
+    DRAG_MOVE,
+    DRAG_RESIZE
+  };
+
+  // If the mouse is currently over a portion of the window that should
+  // trigger a drag or resize, drag_state_ is set appropriately and true
+  // is returned. If the mouse is not over a portion of the window that should
+  // trigger a more or resize, drag_state_ is not updated and false is returend.
+  bool UpdateDragState();
+
+  DragState drag_state_;
+
+  DISALLOW_COPY_AND_ASSIGN(DefaultContainerEventFilter);
+};
+
+}  // namespace internal
+}  // namespace aura_shell
+
+#endif  //  UI_AURA_SHELL_DEFAULT_CONTAINER_EVENT_FILTER_H_