Add WorkspaceObserver to observe changes in workspace state

ui/aura_shell/default_container_layout_manager.h

 // 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_LAYOUT_MANAGER_H_
 #define UI_AURA_SHELL_DEFAULT_CONTAINER_LAYOUT_MANAGER_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ skipping 13 matching lines @@
 namespace aura_shell {
 namespace internal {
 
 class ShowStateController;
 class WorkspaceManager;
 
 // LayoutManager for the default window container.
 class AURA_SHELL_EXPORT DefaultContainerLayoutManager
     : public aura::LayoutManager {
  public:
-  DefaultContainerLayoutManager(aura::Window* owner,
-                                WorkspaceManager* workspace_manager);
+  explicit DefaultContainerLayoutManager(WorkspaceManager* workspace_manager);
   virtual ~DefaultContainerLayoutManager();
 
   // Returns the workspace manager for this container.
   WorkspaceManager* workspace_manager() {
     return workspace_manager_;
   }
 
   // Invoked when a window receives drag event.
   void PrepareForMoveOrResize(aura::Window* drag, aura::MouseEvent* event);
 
   // Invoked when a drag event didn't start any drag operation.
   void CancelMoveOrResize(aura::Window* drag, aura::MouseEvent* event);
 
   // Invoked when a drag event moved the |window|.
   void ProcessMove(aura::Window* window, aura::MouseEvent* event);
 
   // Invoked when a user finished moving window.
   void EndMove(aura::Window* drag, aura::MouseEvent* evnet);
 
   // Invoked when a user finished resizing window.
   void EndResize(aura::Window* drag, aura::MouseEvent* evnet);
 
-  // If true, |SetChildBounds| does not modify the requested bounds.
-  // Use in situations where you want to circumvent what
-  // SetChildBounds() would normally do.
-  void set_ignore_calculate_bounds(bool value) {
-    ignore_calculate_bounds_ = value;
-  }
-
   // Overridden from aura::LayoutManager:
   virtual void OnWindowResized() OVERRIDE;
   virtual void OnWindowAdded(aura::Window* child) OVERRIDE;
   virtual void OnWillRemoveWindow(aura::Window* child) OVERRIDE;
   virtual void OnChildWindowVisibilityChanged(aura::Window* child,
                                               bool visibile) OVERRIDE;
   virtual void SetChildBounds(aura::Window* child,
                               const gfx::Rect& requested_bounds) OVERRIDE;
  private:
-  aura::Window* owner_;
-
+  // Owned by WorkspaceController.
   WorkspaceManager* workspace_manager_;
 
   // A window that are currently moved or resized. Used to put
   // different constraints on drag window.
   aura::Window* drag_window_;
 
-  // A flag to control layout behavior. This is set to true while
-  // workspace manager is laying out children and LayoutManager
-  // ignores bounds check.
-  bool ignore_calculate_bounds_;
-
   scoped_ptr<ShowStateController> show_state_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultContainerLayoutManager);
 };
 
 }  // namespace internal
 }  // namespace aura_shell
 
 #endif  // UI_AURA_SHELL_DEFAULT_CONTAINER_LAYOUT_MANAGER_H_