Implement workspace scrubbing

ash/wm/workspace/workspace_manager.h

Index: ash/wm/workspace/workspace_manager.h
diff --git a/ash/wm/workspace/workspace_manager.h b/ash/wm/workspace/workspace_manager.h
index e59eada1c6ea9d7d1c4898926fc050fcfde8b101..983328eb8547b71030d0f2326be9099f168a8a4b 100644
--- a/ash/wm/workspace/workspace_manager.h
+++ b/ash/wm/workspace/workspace_manager.h
@@ -53,6 +53,12 @@ class Workspace;
 // are maximized and restored they are reparented to the right Window.
 class ASH_EXPORT WorkspaceManager : public ash::ShellObserver {
  public:
+

[sky, 2012/11/28 15:15:34]

remove newline.

+  enum Direction {
+    WORKSPACE_ABOVE,

[sky, 2012/11/28 15:15:34]

Above and below are not clear in this content. How about next/previous and use
cycle here, eg:
CycleDirection {
  CYCLE_NEXT, CYCLE_PREVIOUS
}

+    WORKSPACE_BELOW
+  };
+
   explicit WorkspaceManager(aura::Window* viewport);
   virtual ~WorkspaceManager();
 
@@ -78,9 +84,17 @@ class ASH_EXPORT WorkspaceManager : public ash::ShellObserver {
   // when a new Window is being added.
   aura::Window* GetParentForNewWindow(aura::Window* window);
 
+  // Called by the workspace cycler to activate the next workspace in
+  // |direction|. Returns false if there are no more workspaces to cycle
+  // to in |direction|.
+  bool CycleToWorkspace(Direction direction);
+
   // Starts the animation that occurs on first login.
   void DoInitialAnimation();
 
+  // Returns the window of the currently active workspace.
+  aura::Window* GetActiveWorkspaceWindow() const;

[sky, 2012/11/28 15:15:34]

Should either return const or not be const.

+
   // ShellObserver overrides:
   virtual void OnAppTerminating() OVERRIDE;
 
@@ -106,6 +120,9 @@ class ASH_EXPORT WorkspaceManager : public ash::ShellObserver {
     // rather we run the animations as if a switch occurred.
     SWITCH_INITIAL,
 
+    // Switch as the result of cycling through workspaces.
+    SWITCH_CYCLE_WORKSPACE,
+
     // Edge case. See comment in OnWorkspaceWindowShowStateChanged().  Don't
     // make other types randomly use this!
     SWITCH_OTHER,
@@ -147,8 +164,8 @@ class ASH_EXPORT WorkspaceManager : public ash::ShellObserver {
   // windows. If |stack_beneath| is non-NULL the windows are stacked beneath it.
   void MoveChildrenToDesktop(aura::Window* window, aura::Window* stack_beneath);
 
-  // Selects the next workspace.
-  void SelectNextWorkspace(SwitchReason reason);
+  // Selects the workspace below the active workspace if any.
+  void SelectWorkspaceBelow(SwitchReason reason);

[sky, 2012/11/28 15:15:34]

Keep the old name, its clearer since below doesn't mean anything.

 
   // Schedules |workspace| for deletion when it no longer contains any layers.
   // See comments above |to_delete_| as to why we do this.