Initial cut at scaffolding for mac sidetabs. No visible changes to browser wi...

chrome/browser/tab_menu_model.cc

Index: chrome/browser/tab_menu_model.cc
===================================================================
--- chrome/browser/tab_menu_model.cc	(revision 48662)
+++ chrome/browser/tab_menu_model.cc	(working copy)
@@ -19,11 +19,9 @@
 bool TabMenuModel::AreVerticalTabsEnabled() {
 #if defined(OS_CHROMEOS)
   return true;
-#elif defined(TOOLKIT_VIEWS)
+#elif defined(TOOLKIT_VIEWS) || defined(OS_MACOSX)
   return CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kEnableVerticalTabs);
-#else
-  return false;
 #endif
 }