Move DropTargetEvent back to ui/base for the time being as it depends on OSExchangeData which I don…

ui/ui.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'includes': [
     'shell_dialogs.gypi',
@@ skipping 133 matching lines @@
         'base/dragdrop/cocoa_dnd_util.h',
         'base/dragdrop/cocoa_dnd_util.mm',
         'base/dragdrop/drag_drop_types.h',
         'base/dragdrop/drag_drop_types_win.cc',
         'base/dragdrop/drag_source_win.cc',
         'base/dragdrop/drag_source_win.h',
         'base/dragdrop/drag_utils.cc',
         'base/dragdrop/drag_utils.h',
         'base/dragdrop/drag_utils_aura.cc',
         'base/dragdrop/drag_utils_win.cc',
+        'base/dragdrop/drop_target_event.cc',
+        'base/dragdrop/drop_target_event.h',
         'base/dragdrop/drop_target_win.cc',
         'base/dragdrop/drop_target_win.h',
         'base/dragdrop/gtk_dnd_util.cc',
         'base/dragdrop/gtk_dnd_util.h',
         'base/dragdrop/os_exchange_data.cc',
         'base/dragdrop/os_exchange_data.h',
         'base/dragdrop/os_exchange_data_provider_aurax11.cc',
         'base/dragdrop/os_exchange_data_provider_aurax11.h',
         'base/dragdrop/os_exchange_data_provider_aura.cc',
         'base/dragdrop/os_exchange_data_provider_aura.h',
@@ skipping 716 matching lines @@
         ['use_ozone==0', {
           'sources!': [
             'base/cursor/cursor_null.cc',
             'base/cursor/cursor_loader_null.cc',
             'base/cursor/cursor_loader_null.h',
           ],
         }],
         ['toolkit_views==0', {
           'sources!': [
             'base/x/events_x.cc',
+            'base/dragdrop/drop_target_event.cc',
+            'base/dragdrop/drop_target_event.h',
             'events/event.cc',
             'events/event.h',
             'events/event_dispatcher.cc',
             'events/event_dispatcher.h',
             'events/event_handler.cc',
             'events/event_handler.h',
             'events/event_target.cc',
             'events/event_target.h',
           ],
         }],
@@ skipping 197 matching lines @@
               'xcode_settings': {
                 'GCC_SYMBOLS_PRIVATE_EXTERN': 'NO',
               },
             }],
           ],
         },
       ],
     }],
   ],
 }