Upstream Chrome on iOS source code [9/11].

ios/chrome/browser/ui/tab_switcher/tab_switcher_tab_strip_placeholder_view.h

Index: ios/chrome/browser/ui/tab_switcher/tab_switcher_tab_strip_placeholder_view.h
diff --git a/ios/chrome/browser/ui/tab_switcher/tab_switcher_tab_strip_placeholder_view.h b/ios/chrome/browser/ui/tab_switcher/tab_switcher_tab_strip_placeholder_view.h
new file mode 100644
index 0000000000000000000000000000000000000000..1269c34cd3f9a8dd8124c52cec48fb0a112b22e2
--- /dev/null
+++ b/ios/chrome/browser/ui/tab_switcher/tab_switcher_tab_strip_placeholder_view.h
@@ -0,0 +1,27 @@
+// Copyright 2016 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 IOS_CHROME_BROWSER_UI_TAB_SWITCHER_TAB_SWITCHER_TAB_STRIP_PLACEHOLDER_VIEW_H_
+#define IOS_CHROME_BROWSER_UI_TAB_SWITCHER_TAB_SWITCHER_TAB_STRIP_PLACEHOLDER_VIEW_H_
+
+#import <UIKit/UIKit.h>
+
+#include "base/ios/block_types.h"
+
+// Used has a placeholder for the tab strip view during the tab switcher
+// controller transition animations.
+@interface TabSwitcherTabStripPlaceholderView : UIView
+
+// Triggers a fold animation of the tab strip placeholder resulting
+// in hiding all the tabs views. |completion| is called at the end of the
+// animation.
+- (void)foldWithCompletion:(ProceduralBlock)completion;
+
+// Triggers an unfold animation of the tab strip placeholder resulting in
+// showing the tabs views. |completion| is called at the end of the animation.
+- (void)unfoldWithCompletion:(ProceduralBlock)completion;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_TAB_SWITCHER_TAB_SWITCHER_TAB_STRIP_PLACEHOLDER_VIEW_H_