Add support for X11 workspaces

ui/views/widget/desktop_aura/desktop_native_widget_aura.h

Index: ui/views/widget/desktop_aura/desktop_native_widget_aura.h
diff --git a/ui/views/widget/desktop_aura/desktop_native_widget_aura.h b/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
index a8c42b6ab896c5ef37bd0c90e87d7c0037391067..338d5bdc9af820990865cd7ef130b6f5c4dae315 100644
--- a/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
+++ b/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
@@ -123,6 +123,7 @@ class VIEWS_EXPORT DesktopNativeWidgetAura
   gfx::Rect GetWindowBoundsInScreen() const override;
   gfx::Rect GetClientAreaBoundsInScreen() const override;
   gfx::Rect GetRestoredBounds() const override;
+  int GetRestoredWorkspace() const override;
   void SetBounds(const gfx::Rect& bounds) override;
   void SetSize(const gfx::Size& size) override;
   void StackAbove(gfx::NativeView native_view) override;
@@ -225,6 +226,8 @@ class VIEWS_EXPORT DesktopNativeWidgetAura
   // Overridden from aura::WindowTreeHostObserver:
   void OnHostCloseRequested(const aura::WindowTreeHost* host) override;
   void OnHostResized(const aura::WindowTreeHost* host) override;
+  void OnHostWorkspaceChanged(const aura::WindowTreeHost* host,
+                              int workspace_id) override;
   void OnHostMoved(const aura::WindowTreeHost* host,
                    const gfx::Point& new_origin) override;