Use Ash's ShelfWindowWatcher for app panel windows.

ash/common/shelf/shelf_window_watcher_item_delegate.cc

Index: ash/common/shelf/shelf_window_watcher_item_delegate.cc
diff --git a/ash/common/shelf/shelf_window_watcher_item_delegate.cc b/ash/common/shelf/shelf_window_watcher_item_delegate.cc
index a1450e171d42059cb1f0af117e2f9180ea446c36..e1dc5ce981de3c3e9c73dd2cfb52166d0bb460d0 100644
--- a/ash/common/shelf/shelf_window_watcher_item_delegate.cc
+++ b/ash/common/shelf/shelf_window_watcher_item_delegate.cc
@@ -4,18 +4,44 @@
 
 #include "ash/common/shelf/shelf_window_watcher_item_delegate.h"
 
+#include "ash/common/shelf/shelf_controller.h"
+#include "ash/common/shelf/shelf_model.h"
+#include "ash/common/wm/window_state.h"
+#include "ash/common/wm_shell.h"
 #include "ash/common/wm_window.h"
 #include "ui/events/event.h"
 
 namespace ash {
 
-ShelfWindowWatcherItemDelegate::ShelfWindowWatcherItemDelegate(WmWindow* window)
-    : window_(window) {}
+namespace {
+
+ShelfItemType GetShelfItemType(ShelfID id) {
+  ShelfModel* model = WmShell::Get()->shelf_controller()->model();
+  ShelfItems::const_iterator item = model->ItemByID(id);
+  return item == model->items().end() ? TYPE_UNDEFINED : item->type;
+}
+
+}  // namespace
+
+ShelfWindowWatcherItemDelegate::ShelfWindowWatcherItemDelegate(ShelfID id,
+                                                               WmWindow* window)
+    : id_(id), window_(window) {
+  DCHECK_NE(kInvalidShelfID, id_);
+  DCHECK(window_);
+}
 
 ShelfWindowWatcherItemDelegate::~ShelfWindowWatcherItemDelegate() {}
 
 ShelfItemDelegate::PerformedAction ShelfWindowWatcherItemDelegate::ItemSelected(
     const ui::Event& event) {
+  // Move panels attached on another display to the current display.
+  if (GetShelfItemType(id_) == TYPE_APP_PANEL &&
+      window_->GetWindowState()->panel_attached() &&
+      window_->MoveToEventRoot(event)) {
+    window_->Activate();
+    return kExistingWindowActivated;
+  }
+
   if (window_->IsActive()) {
     if (event.type() & ui::ET_KEY_RELEASED) {
       window_->Animate(::wm::WINDOW_ANIMATION_TYPE_BOUNCE);
@@ -42,11 +68,13 @@ bool ShelfWindowWatcherItemDelegate::IsDraggable() {
 }
 
 bool ShelfWindowWatcherItemDelegate::CanPin() const {
-  return true;
+  return GetShelfItemType(id_) != TYPE_APP_PANEL;
 }
 
 bool ShelfWindowWatcherItemDelegate::ShouldShowTooltip() {
-  return true;
+  // Do not show tooltips for visible attached app panel windows.
+  return GetShelfItemType(id_) != TYPE_APP_PANEL || !window_->IsVisible() ||
+         !window_->GetWindowState()->panel_attached();
 }
 
 void ShelfWindowWatcherItemDelegate::Close() {