Update shelf when overlapping dragged windows exist

ash/wm/dock/docked_window_layout_manager.cc

 // Copyright (c) 2013 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/dock/docked_window_layout_manager.h"
 
 #include "ash/ash_switches.h"
 #include "ash/launcher/launcher.h"
 #include "ash/screen_ash.h"
 #include "ash/shelf/shelf_layout_manager.h"
@@ skipping 465 matching lines @@
     wm::GetWindowState(child)->Restore();
   Relayout();
   UpdateDockBounds(DockedWindowLayoutManagerObserver::CHILD_CHANGED);
 }
 
 void DockedWindowLayoutManager::SetChildBounds(
     aura::Window* child,
     const gfx::Rect& requested_bounds) {
   // Whenever one of our windows is moved or resized enforce layout.
   SetChildBoundsDirect(child, requested_bounds);
+  if (IsPopupOrTransient(child))
+    return;
+  ShelfLayoutManager* shelf_layout = internal::ShelfLayoutManager::ForLauncher(
+      dock_container_);
+  if (shelf_layout)
+    shelf_layout->UpdateVisibilityState();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // DockLayoutManager, ash::ShellObserver implementation:
 
 void DockedWindowLayoutManager::OnDisplayWorkAreaInsetsChanged() {
   Relayout();
   UpdateDockBounds(DockedWindowLayoutManagerObserver::DISPLAY_INSETS_CHANGED);
   MaybeMinimizeChildrenExcept(dragged_window_);
 }
@@ skipping 567 matching lines @@
 void DockedWindowLayoutManager::OnKeyboardBoundsChanging(
     const gfx::Rect& keyboard_bounds) {
   // This bounds change will have caused a change to the Shelf which does not
   // propagate automatically to this class, so manually recalculate bounds.
   Relayout();
   UpdateDockBounds(DockedWindowLayoutManagerObserver::KEYBOARD_BOUNDS_CHANGING);
 }
 
 }  // namespace internal
 }  // namespace ash