Added the "Show as Tab" option for popups on OSX

chrome/browser/ui/cocoa/browser_window_command_handler.mm

 // Copyright 2015 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/ui/cocoa/browser_window_command_handler.h"
 
 #include "base/logging.h"
 #import "base/mac/foundation_util.h"
 #include "chrome/app/chrome_command_ids.h"
 #import "chrome/browser/app_controller_mac.h"
@@ skipping 201 matching lines @@
       NSMenuItem* menuItem = base::mac::ObjCCast<NSMenuItem>(item);
       [menuItem setHidden:shouldHide];
       break;
     }
     case IDC_TOGGLE_FULLSCREEN_TOOLBAR: {
       if (!chrome::mac::SupportsSystemFullscreen()) {
         NSMenuItem* menuItem = base::mac::ObjCCast<NSMenuItem>(item);
         [menuItem setHidden:YES];
         enable = NO;
       }
+      break;
+    }
+    case IDC_SHOW_AS_TAB: {
+      // Hide this menu option if the window is tabbed.
+      NSMenuItem* menuItem = base::mac::ObjCCast<NSMenuItem>(item);
+      [menuItem setHidden:browser->is_type_tabbed()];
+      break;
     }
     default:
       // Special handling for the contents of the Text Encoding submenu. On
       // Mac OS, instead of enabling/disabling the top-level menu item, we
       // enable/disable the submenu's contents (per Apple's HIG).
       EncodingMenuController encoding_controller;
       if (encoding_controller.DoesCommandBelongToEncodingMenu(tag))
         enable &= chrome::IsCommandEnabled(browser, IDC_ENCODING_MENU);
   }
 
@@ skipping 34 matching lines @@
     // the background" in this case.
     modifierFlags &= ~NSCommandKeyMask;
   }
   chrome::ExecuteCommandWithDisposition(
       FindBrowserForSender(sender, window), command,
       ui::WindowOpenDispositionFromNSEventWithFlags([NSApp currentEvent],
                                                     modifierFlags));
 }
 
 @end