ash: Add launcher overflow bubble.

ash/launcher/overflow_bubble.h

Index: ash/launcher/overflow_bubble.h
diff --git a/ash/launcher/overflow_bubble.h b/ash/launcher/overflow_bubble.h
new file mode 100644
index 0000000000000000000000000000000000000000..aa2d0e32f36a445cbf78a2a52b5e4978119fd3dc
--- /dev/null
+++ b/ash/launcher/overflow_bubble.h
@@ -0,0 +1,54 @@
+// 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.
+
+#ifndef ASH_LAUNCHER_OVERFLOW_BUBBLE_H_
+#define ASH_LAUNCHER_OVERFLOW_BUBBLE_H_
+
+#include "ash/wm/shelf_types.h"
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "ui/views/widget/widget.h"
+
+namespace views {
+class View;
+}
+
+namespace ash {
+
+class LauncherDelegate;
+class LauncherModel;
+
+namespace internal {
+
+class LauncherView;
+
+// OverflowBubble displays an overflow bubble.
+class OverflowBubble : public views::Widget::Observer {
+ public:
+  OverflowBubble();
+  virtual ~OverflowBubble();
+
+  void Show(LauncherDelegate* delegate,
+            LauncherModel* model,
+            views::View* anchor,
+            ShelfAlignment shelf_alignment,
+            int overflow_start_index);
+
+  void Hide();
+
+  bool IsShowing() const { return !!bubble_; }
+
+ private:
+  // views::Widget::Observer overrides:
+  virtual void OnWidgetClosing(views::Widget* widget) OVERRIDE;
+
+  views::View* bubble_;  // Owned by views hierarchy.
+
+  DISALLOW_COPY_AND_ASSIGN(OverflowBubble);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_LAUNCHER_OVERFLOW_BUBBLE_H_