Prevents panels attached to shelf from docking

ash/wm/window_state.cc

Index: ash/wm/window_state.cc
diff --git a/ash/wm/window_state.cc b/ash/wm/window_state.cc
index 0c86e28499dad3fb9662cd1baf1d9fd3e0fd3c3d..185372e5eab24982323ab776eef30680cf98f4f5 100644
--- a/ash/wm/window_state.cc
+++ b/ash/wm/window_state.cc
@@ -33,7 +33,6 @@ WindowState::WindowState(aura::Window* window)
       ignored_by_shelf_(false),
       can_consume_system_keys_(false),
       top_row_keys_are_function_keys_(false),
-      window_resizer_(NULL),
       always_restores_to_restore_bounds_(false),
       hide_shelf_when_fullscreen_(true),
       animate_to_fullscreen_(true),
@@ -252,6 +251,22 @@ void WindowState::RemoveObserver(WindowStateObserver* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
+bool WindowState::CreateDragDetails(aura::Window* window,
+                                    const gfx::Point& point_in_parent,
+                                    int window_component,
+                                    aura::client::WindowMoveSource source) {
+  scoped_ptr<DragDetails> details(new DragDetails(
+        window, point_in_parent, window_component, source));
+  if (!details->is_resizable)
+    return false;
+  drag_details_ = details.Pass();
+  return true;
+}
+
+void WindowState::DeleteDragDetails() {
+  drag_details_.reset();
+}
+
 void WindowState::OnWindowPropertyChanged(aura::Window* window,
                                           const void* key,
                                           intptr_t old) {