Reworks the workspace code. Here's the new heuristics:

ash/wm/workspace/workspace_layout_manager.h

Index: ash/wm/workspace/workspace_layout_manager.h
diff --git a/ash/wm/workspace/workspace_layout_manager.h b/ash/wm/workspace/workspace_layout_manager.h
index 3fdceb8151ad6012399aa6fed9a495fb81c22577..4a1ca87929e61630307f871b295f53620f84e8a2 100644
--- a/ash/wm/workspace/workspace_layout_manager.h
+++ b/ash/wm/workspace/workspace_layout_manager.h
@@ -6,11 +6,10 @@
 #define ASH_WM_WORKSPACE_WORKSPACE_LAYOUT_MANAGER_H_
 #pragma once
 
+#include "ash/ash_export.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
-#include "base/memory/scoped_ptr.h"
 #include "ui/aura/layout_manager.h"
-#include "ash/ash_export.h"
 
 namespace aura {
 class MouseEvent;
@@ -24,10 +23,9 @@ class Rect;
 namespace ash {
 namespace internal {
 
-class ShowStateController;
 class WorkspaceManager;
 
-// LayoutManager for the default window container.
+// LayoutManager for top level windows when WorkspaceManager is enabled.
 class ASH_EXPORT WorkspaceLayoutManager : public aura::LayoutManager {
  public:
   explicit WorkspaceLayoutManager(WorkspaceManager* workspace_manager);
@@ -61,12 +59,11 @@ class ASH_EXPORT WorkspaceLayoutManager : public aura::LayoutManager {
                                               bool visibile) OVERRIDE;
   virtual void SetChildBounds(aura::Window* child,
                               const gfx::Rect& requested_bounds) OVERRIDE;
+
  private:
   // Owned by WorkspaceController.
   WorkspaceManager* workspace_manager_;
 
-  scoped_ptr<ShowStateController> show_state_controller_;
-
   DISALLOW_COPY_AND_ASSIGN(WorkspaceLayoutManager);
 };