Creates BrowserTabStripTracker to consolidate common code

chrome/browser/ui/browser_tab_strip_tracker_delegate.h

+// Copyright 2015 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_BROWSER_TAB_STRIP_TRACKER_DELEGATE_H_
+#define CHROME_BROWSER_UI_BROWSER_TAB_STRIP_TRACKER_DELEGATE_H_
+
+#include "chrome/browser/ui/browser_list_observer.h"
+
+class Browser;
+
+class BrowserTabStripTrackerDelegate {
+ public:
+  // Called to determine if the supplied Browser should be tracked. See
+  // BrowserTabStripTracker for details.
+  virtual bool ShouldTrackBrowser(Browser* browser) = 0;
+
+ protected:
+  virtual ~BrowserTabStripTrackerDelegate() {}
+};
+
+#endif  // CHROME_BROWSER_UI_BROWSER_TAB_STRIP_TRACKER_DELEGATE_H_