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

ios/chrome/browser/ui/tabs/tab_strip_view.h

+// Copyright 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 IOS_CHROME_BROWSER_UI_TABS_TAB_STRIP_VIEW_H_
+#define IOS_CHROME_BROWSER_UI_TABS_TAB_STRIP_VIEW_H_
+
+#import <UIKit/UIKit.h>
+
+// Notification sent by the tab strip when its frame changes.
+extern NSString* const kTabStripViewFrameDidChangeNotification;
+
+// TabStripView does not lay out its own subviews, instead handing that off to a
+// delegate.  This protocol is implemented by TabStripView delegates that are
+// capable of handling layout.
+// The TabStripViewLayoutDelegate also forward notification of change of trait
+// collection that impact layout.
+@protocol TabStripViewLayoutDelegate
+// Called from |-layoutSubviews|.  Delegates should implement this method to
+// layout subviews based on the current contentOffset of the tab strip.
+// TabStripView does not perform any other subview layout.
+- (void)layoutTabStripSubviews;
+// Called from UIView |-traitCollectionDidChange:|.
+- (void)traitCollectionDidChange:(UITraitCollection*)previousTraitCollection;
+@end
+
+// View class for the tabstrip.  Contains one TabView per open tab and manages
+// tab overflow behavior.
+@interface TabStripView : UIScrollView {
+ @private
+  id<TabStripViewLayoutDelegate> layoutDelegate_;
+}
+
+@property(nonatomic, readwrite, assign) id<TabStripViewLayoutDelegate>
+    layoutDelegate;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_TABS_TAB_STRIP_VIEW_H_