Makes the TabStrip always have the ability to enter stacking mode on

chrome/browser/ui/views/tabs/browser_tab_strip_controller.cc

 // Copyright (c) 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.
 
 #include "chrome/browser/ui/views/tabs/browser_tab_strip_controller.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/tab_helper.h"
@@ skipping 41 matching lines @@
   return TabRendererData::NETWORK_STATE_LOADING;
 }
 
 TabStripLayoutType DetermineTabStripLayout(PrefService* prefs,
                                            bool* adjust_layout) {
   *adjust_layout = false;
   if (CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableStackedTabStrip)) {
     return TAB_STRIP_LAYOUT_STACKED;
   }
+  // For chromeos always allow entering stacked mode.
+#if !defined(OS_CHROMEOS)
   if (ui::GetDisplayLayout() != ui::LAYOUT_TOUCH)
     return TAB_STRIP_LAYOUT_SHRINK;
+#endif
   *adjust_layout = true;
   switch (prefs->GetInteger(prefs::kTabStripLayoutType)) {
     case TAB_STRIP_LAYOUT_STACKED:
       return TAB_STRIP_LAYOUT_STACKED;
     default:
       return TAB_STRIP_LAYOUT_SHRINK;
   }
 }
 
 }  // namespace
@@ skipping 502 matching lines @@
   SetTabRendererDataFromModel(contents->web_contents(), index, &data, NEW_TAB);
   tabstrip_->AddTabAt(index, data, is_active);
 }
 
 void BrowserTabStripController::UpdateLayoutType() {
   bool adjust_layout = false;
   TabStripLayoutType layout_type =
       DetermineTabStripLayout(g_browser_process->local_state(), &adjust_layout);
   tabstrip_->SetLayoutType(layout_type, adjust_layout);
 }