Avoid unnecessary visibility changes to BookmarkBarView

chrome/browser/ui/views/bookmarks/bookmark_bar_view_observer.h

Index: chrome/browser/ui/views/bookmarks/bookmark_bar_view_observer.h
diff --git a/chrome/browser/ui/views/bookmarks/bookmark_bar_view_observer.h b/chrome/browser/ui/views/bookmarks/bookmark_bar_view_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..fa3526c8bf5f561e1049fe9adb55a655d663958a
--- /dev/null
+++ b/chrome/browser/ui/views/bookmarks/bookmark_bar_view_observer.h
@@ -0,0 +1,16 @@
+// Copyright 2014 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 CHROME_BROWSER_UI_VIEWS_BOOKMARKS_BOOKMARK_BAR_VIEW_OBSERVER_H_
+#define CHROME_BROWSER_UI_VIEWS_BOOKMARKS_BOOKMARK_BAR_VIEW_OBSERVER_H_
+
+class BookmarkBarViewObserver {
+ public:
+  virtual void OnBookmarkBarVisibilityChanged() = 0;
+
+ protected:
+  ~BookmarkBarViewObserver() {}
+};
+
+#endif  // CHROME_BROWSER_UI_VIEWS_BOOKMARKS_BOOKMARK_BAR_VIEW_OBSERVER_H_