Makes sure shelf visibility is updated when the visibility of a window

ash/wm/workspace/workspace_manager2.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/wm/workspace/workspace_manager2.h"
 
 #include <algorithm>
 #include <functional>
 
 #include "ash/ash_switches.h"
@@ skipping 151 matching lines @@
   if (!shelf_)
     return WORKSPACE_WINDOW_STATE_DEFAULT;
 
   const gfx::Rect shelf_bounds(shelf_->GetIdealBounds());
   const Window::Windows& windows(active_workspace_->window()->children());
   bool window_overlaps_launcher = false;
   bool has_maximized_window = false;
   for (Window::Windows::const_iterator i = windows.begin();
        i != windows.end(); ++i) {
     ui::Layer* layer = (*i)->layer();
-    if (!layer->GetTargetVisibility() || layer->GetTargetOpacity() == 0.0f ||
-        (*i)->id() == kShellWindowId_DesktopBackgroundContainer)
+    if (!layer->GetTargetVisibility() || layer->GetTargetOpacity() == 0.0f)
       continue;
     if (wm::IsWindowMaximized(*i)) {
       // An untracked window may still be fullscreen so we keep iterating when
       // we hit a maximized window.
       has_maximized_window = true;
     } else if (wm::IsWindowFullscreen(*i)) {
       return WORKSPACE_WINDOW_STATE_FULL_SCREEN;
     }
     if (!window_overlaps_launcher && (*i)->bounds().Intersects(shelf_bounds))
       window_overlaps_launcher = true;
@@ skipping 222 matching lines @@
                                                      Window* child) {
   if (workspace->ShouldMoveToPending())
     MoveWorkspaceToPendingOrDelete(workspace, NULL, ANIMATE_NEW);
 }
 
 void WorkspaceManager2::OnWorkspaceChildWindowVisibilityChanged(
     Workspace2* workspace,
     Window* child) {
   if (workspace->ShouldMoveToPending())
     MoveWorkspaceToPendingOrDelete(workspace, NULL, ANIMATE_NEW);
+  else if (workspace == active_workspace_)
+    UpdateShelfVisibility();
 }
 
 void WorkspaceManager2::OnWorkspaceWindowChildBoundsChanged(
     Workspace2* workspace,
     Window* child) {
   if (workspace == active_workspace_)
     UpdateShelfVisibility();
 }
 
 void WorkspaceManager2::OnWorkspaceWindowShowStateChanged(
@@ skipping 42 matching lines @@
           child, old_layer);
     } else {
       DCHECK(!old_layer);
     }
   }
   UpdateShelfVisibility();
 }
 
 }  // namespace internal
 }  // namespace ash