ash/immersive mode: Hide the launcher when entering immersive mode

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 79bf0acd3b891f050d3b27adf166674e859aff80..08a50bbef07dcb04226ddc55a1b0202ecd8ff69c 100644
--- a/ash/wm/workspace/workspace_manager.h
+++ b/ash/wm/workspace/workspace_manager.h
@@ -79,6 +79,9 @@ class ASH_EXPORT WorkspaceManager : public ash::ShellObserver {
   // NULL or not contained in a workspace.
   void SetActiveWorkspaceByWindow(aura::Window* window);
 
+  // Returns the container window for the active workspace, never NULL.
+  aura::Window* GetActiveWorkspaceWindow();
+
   // Returns the parent for |window|. This is invoked from StackingController
   // when a new Window is being added.
   aura::Window* GetParentForNewWindow(aura::Window* window);