Moves WorkspaceController to ash/common

ash/common/wm/workspace_controller.h

Index: ash/common/wm/workspace_controller.h
diff --git a/ash/wm/workspace_controller.h b/ash/common/wm/workspace_controller.h
similarity index 79%
rename from ash/wm/workspace_controller.h
rename to ash/common/wm/workspace_controller.h
index 610a65f842f6a9379e26f54dc4f5b4da7376aeea..3df40d0fafc76fb8ddbc5d487a73c5016379c49f 100644
--- a/ash/wm/workspace_controller.h
+++ b/ash/common/wm/workspace_controller.h
@@ -2,13 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef ASH_WM_WORKSPACE_CONTROLLER_H_
-#define ASH_WM_WORKSPACE_CONTROLLER_H_
+#ifndef ASH_COMMON_WM_WORKSPACE_CONTROLLER_H_
+#define ASH_COMMON_WM_WORKSPACE_CONTROLLER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
 #include "ash/common/wm/workspace/workspace_types.h"
+#include "ash/common/wm_window_observer.h"
 #include "base/macros.h"
 
 namespace ash {
@@ -20,10 +21,10 @@ class WorkspaceLayoutManagerBackdropDelegate;
 
 // WorkspaceController acts as a central place that ties together all the
 // various workspace pieces.
-class ASH_EXPORT WorkspaceController {
+class ASH_EXPORT WorkspaceController : public WmWindowObserver {

[msw, 2016/08/30 17:46:20]

nit: it'd be nice if you could cleanup
WmRootWindowController::SetMaximizeBackdropDelegate (perhaps in the next CL)
https://cs.chromium.org/chromium/src/ash/common/wm_root_window_controller.h?r...

[sky, 2016/08/30 17:55:09]

Yes, I was planning on doing that once I merge RootWindowControllerCommon into
WmRootWindowController.

  public:
   explicit WorkspaceController(WmWindow* viewport);
-  virtual ~WorkspaceController();
+  ~WorkspaceController() override;
 
   // Returns the current window state.
   wm::WorkspaceWindowState GetWindowState() const;
@@ -41,6 +42,9 @@ class ASH_EXPORT WorkspaceController {
  private:
   friend class WorkspaceControllerTestHelper;
 
+  // WmWindowObserver:
+  void OnWindowDestroying(WmWindow* window) override;
+
   WmWindow* viewport_;
   std::unique_ptr<WorkspaceEventHandler> event_handler_;
 
@@ -52,4 +56,4 @@ class ASH_EXPORT WorkspaceController {
 
 }  // namespace ash
 
-#endif  // ASH_WM_WORKSPACE_CONTROLLER_H_
+#endif  // ASH_COMMON_WM_WORKSPACE_CONTROLLER_H_