[mus+ash] Removes WmWindow from ash/wm/overview and ash/wm/workspace

ash/mus/bridge/shell_port_mash.h

Index: ash/mus/bridge/shell_port_mash.h
diff --git a/ash/mus/bridge/shell_port_mash.h b/ash/mus/bridge/shell_port_mash.h
index 2624227b90bccf11525cbf5fb66b773b8d1af4cd..3470f5064dd113156bfd0d6829b9ee370d71c048 100644
--- a/ash/mus/bridge/shell_port_mash.h
+++ b/ash/mus/bridge/shell_port_mash.h
@@ -70,7 +70,7 @@ class ShellPortMash : public ShellPort, public WindowTreeHostManager::Observer {
   display::Display GetFirstDisplay() const override;
   bool IsInUnifiedMode() const override;
   bool IsInUnifiedModeIgnoreMirroring() const override;
-  void SetDisplayWorkAreaInsets(WmWindow* window,
+  void SetDisplayWorkAreaInsets(aura::Window* window,
                                 const gfx::Insets& insets) override;
   std::unique_ptr<display::TouchTransformSetter> CreateTouchTransformDelegate()
       override;
@@ -92,7 +92,7 @@ class ShellPortMash : public ShellPort, public WindowTreeHostManager::Observer {
   std::unique_ptr<wm::TabletModeEventHandler> CreateTabletModeEventHandler()
       override;
   std::unique_ptr<WorkspaceEventHandler> CreateWorkspaceEventHandler(
-      WmWindow* workspace_window) override;
+      aura::Window* workspace_window) override;
   std::unique_ptr<ScopedDisableInternalMouseAndKeyboard>
   CreateScopedDisableInternalMouseAndKeyboard() override;
   std::unique_ptr<ImmersiveFullscreenController>