linux_aura: Default to system titlebars under some window managers.

chrome/browser/ui/gtk/browser_window_gtk.h

 // Copyright 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.
 
 #ifndef CHROME_BROWSER_UI_GTK_BROWSER_WINDOW_GTK_H_
 #define CHROME_BROWSER_UI_GTK_BROWSER_WINDOW_GTK_H_
 
 #include <gtk/gtk.h>
 
 #include <string>
@@ skipping 454 matching lines @@
 
   // Shows docked devtools.
   void ShowDevToolsContainer();
 
   // Hides docked devtools.
   void HideDevToolsContainer();
 
   // Called when the preference changes.
   void OnUseCustomChromeFrameChanged();
 
-  // Determine whether we use should default to native decorations or the custom
-  // frame based on the currently-running window manager.
-  static bool GetCustomFramePrefDefault();
-
   // Handler for |devtools_floating_container_|'s "set-floating-position"
   // signal.
   static void OnDevToolsContainerSetFloatingPosition(
       GtkFloatingContainer* container, GtkAllocation* allocation,
       BrowserWindowGtk* browser_window);
 
   // The position and size of the current window.
   gfx::Rect bounds_;
 
   // The configure bounds of the current window, used to figure out whether to
@@ skipping 96 matching lines @@
   bool is_fullscreen_;
 
   scoped_ptr<FullscreenExitBubbleGtk> fullscreen_exit_bubble_;
 
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserWindowGtk);
 };
 
 #endif  // CHROME_BROWSER_UI_GTK_BROWSER_WINDOW_GTK_H_