Add a flag that lets the webstore show a different UI on app install.

chrome/browser/ui/touch/tabs/touch_tab_strip.h

 // Copyright (c) 2011 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_TOUCH_TABS_TOUCH_TAB_STRIP_H_
 #define CHROME_BROWSER_UI_TOUCH_TABS_TOUCH_TAB_STRIP_H_
 #pragma once
 
 #include "chrome/browser/ui/views/tabs/base_tab_strip.h"
 
@@ skipping 14 matching lines @@
 //      container for Tabs, and is also responsible for creating them.
 //
 // TODO(wyck): Use transformable views for scrolling.
 ///////////////////////////////////////////////////////////////////////////////
 class TouchTabStrip : public BaseTabStrip {
  public:
   explicit TouchTabStrip(TabStripController* controller);
   virtual ~TouchTabStrip();
 
   // AbstractTabStripView implementation:
-  virtual bool IsPositionInWindowCaption(const gfx::Point& point);
-  virtual void SetBackgroundOffset(const gfx::Point& offset);
+  virtual bool IsPositionInWindowCaption(const gfx::Point& point) OVERRIDE;
+  virtual void SetBackgroundOffset(const gfx::Point& offset) OVERRIDE;
+  virtual views::View* GetNewTabButton() OVERRIDE;
 
   // BaseTabStrip implementation:
   virtual void PrepareForCloseAt(int model_index);
   virtual void StartHighlight(int model_index);
   virtual void StopAllHighlighting();
   virtual BaseTab* CreateTabForDragging();
   virtual void RemoveTabAt(int model_index);
   virtual void SetSelection(const TabStripSelectionModel& old_selection,
                             const TabStripSelectionModel& new_selection);
   virtual void TabTitleChangedNotLoading(int model_index);
@@ skipping 87 matching lines @@
   TouchTab* initial_tab_;
 
   // The minimum value that |scroll_offset_| can have.  Based on the total
   // width of all the content to be scrolled, less the viewport size.
   int min_scroll_offset_;
 
   DISALLOW_COPY_AND_ASSIGN(TouchTabStrip);
 };
 
 #endif  // CHROME_BROWSER_UI_TOUCH_TABS_TOUCH_TAB_STRIP_H_