Revert r42156, r42157, r42160. Allow dynamic switching in and out of sidetabs...

chrome/browser/tabs/tab_strip_model.h

Index: chrome/browser/tabs/tab_strip_model.h
===================================================================
--- chrome/browser/tabs/tab_strip_model.h	(revision 42174)
+++ chrome/browser/tabs/tab_strip_model.h	(working copy)
@@ -223,12 +223,6 @@
 
   // Creates a bookmark folder containing a bookmark for all open tabs.
   virtual void BookmarkAllTabs() = 0;
-
-  // Returns true if the vertical tabstrip presentation should be used.
-  virtual bool UseVerticalTabs() const = 0;
-
-  // Toggles the use of the vertical tabstrip.
-  virtual void ToggleUseVerticalTabs() = 0;
 };
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -553,7 +547,6 @@
     CommandRestoreTab,
     CommandTogglePinned,
     CommandBookmarkAllTabs,
-    CommandUseVerticalTabs,
     CommandLast
   };
 
@@ -561,10 +554,6 @@
   bool IsContextMenuCommandEnabled(int context_index,
                                    ContextMenuCommand command_id) const;
 
-  // Returns true if the specified command is checked.
-  bool IsContextMenuCommandChecked(int context_index,
-                                   ContextMenuCommand command_id) const;
-
   // Performs the action associated with the specified command for the given
   // TabStripModel index |context_index|.
   void ExecuteContextMenuCommand(int context_index,