mac: Remove IsOSLion().

chrome/browser/fullscreen_mac.mm

 // 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.
 
 #import "chrome/browser/fullscreen.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/command_line.h"
-#include "base/mac/mac_util.h"
 #include "base/mac/sdk_forward_declarations.h"
 #include "chrome/common/chrome_switches.h"
 
 bool IsFullScreenMode() {
   // Check if the main display has been captured (by games in particular).
   if (CGDisplayIsCaptured(CGMainDisplayID()))
     return true;
 
   NSApplicationPresentationOptions options =
       [NSApp currentSystemPresentationOptions];
@@ skipping 12 matching lines @@
   if (options & NSApplicationPresentationFullScreen)
     return true;
 
   return false;
 }
 
 namespace chrome {
 namespace mac {
 
 bool SupportsSystemFullscreen() {
-  return base::mac::IsOSLionOrLater();
+  // TODO(spqchan): Clean this up, https://crbug.com/579259
+  return true;
 }
 
 }  // namespace mac
 }  // namespace chrome