[Mac] Refactor the logic of tab dragging out of TabView and into a new helper.

chrome/chrome_browser.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'browser',
       'type': 'static_library',
       'msvs_guid': '5BF908A7-68FB-4A4B-99E3-8C749F1FE4EA',
@@ skipping 2540 matching lines @@
         'browser/ui/cocoa/tabpose_window.h',
         'browser/ui/cocoa/tabpose_window.mm',
         'browser/ui/cocoa/tabs/side_tab_strip_controller.h',
         'browser/ui/cocoa/tabs/side_tab_strip_controller.mm',
         'browser/ui/cocoa/tabs/side_tab_strip_view.h',
         'browser/ui/cocoa/tabs/side_tab_strip_view.mm',
         'browser/ui/cocoa/tabs/tab_controller.h',
         'browser/ui/cocoa/tabs/tab_controller.mm',
         'browser/ui/cocoa/tabs/tab_strip_controller.h',
         'browser/ui/cocoa/tabs/tab_strip_controller.mm',
+        'browser/ui/cocoa/tabs/tab_strip_drag_controller.h',
+        'browser/ui/cocoa/tabs/tab_strip_drag_controller.mm',
         'browser/ui/cocoa/tabs/tab_strip_model_observer_bridge.h',
         'browser/ui/cocoa/tabs/tab_strip_model_observer_bridge.mm',
         'browser/ui/cocoa/tabs/tab_strip_view.h',
         'browser/ui/cocoa/tabs/tab_strip_view.mm',
         'browser/ui/cocoa/tabs/tab_view.h',
         'browser/ui/cocoa/tabs/tab_view.mm',
         'browser/ui/cocoa/tabs/tab_window_controller.h',
         'browser/ui/cocoa/tabs/tab_window_controller.mm',
         'browser/ui/cocoa/tabs/throbber_view.h',
         'browser/ui/cocoa/tabs/throbber_view.mm',
@@ skipping 2051 matching lines @@
       'hard_dependency': 1,
     },
   ],
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: