Makes the launcher auto-hide for maximized windows. This turned out to

ash/shell.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/shell.h"
 
 #include <algorithm>
 
 #include "ash/app_list/app_list.h"
 #include "ash/ash_switches.h"
@@ skipping 718 matching lines @@
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Shell, private:
 
 void Shell::InitLayoutManagers() {
   DCHECK(root_window_layout_);
   DCHECK(status_widget_);
 
   internal::ShelfLayoutManager* shelf_layout_manager =
-      new internal::ShelfLayoutManager(launcher_->widget(), status_widget_);
+      new internal::ShelfLayoutManager(status_widget_);
+  shelf_layout_manager->SetLauncher(launcher_.get());
   GetContainer(internal::kShellWindowId_LauncherContainer)->
       SetLayoutManager(shelf_layout_manager);
   shelf_ = shelf_layout_manager;
 
   internal::StatusAreaLayoutManager* status_area_layout_manager =
       new internal::StatusAreaLayoutManager(shelf_layout_manager);
   GetContainer(internal::kShellWindowId_StatusContainer)->
       SetLayoutManager(status_area_layout_manager);
 
   aura::Window* default_container =
       GetContainer(internal::kShellWindowId_DefaultContainer);
   // Workspace manager has its own layout managers.
   workspace_controller_.reset(
       new internal::WorkspaceController(default_container));
   workspace_controller_->workspace_manager()->set_shelf(shelf_layout_manager);
 
   // Ensure launcher is visible.
   launcher_->widget()->Show();
 
   // Create the desktop background image.
   desktop_background_controller_->SetDefaultDesktopBackgroundImage();
 }
 
 void Shell::DisableWorkspaceGridLayout() {
   if (workspace_controller_.get())
     workspace_controller_->workspace_manager()->set_grid_size(0);
 }
 
 }  // namespace ash