linux_aura: Fix crash when dragging NTP icons.

ui/ui_unittests.gypi

Index: ui/ui_unittests.gypi
diff --git a/ui/ui_unittests.gypi b/ui/ui_unittests.gypi
index e62af9376f8853d9d15063760ab06636002325e7..e54e963234926af8c4d7e1bff11d527e25e76f06 100644
--- a/ui/ui_unittests.gypi
+++ b/ui/ui_unittests.gypi
@@ -152,6 +152,7 @@
         'base/cocoa/menu_controller_unittest.mm',
         'base/cocoa/nsgraphics_context_additions_unittest.mm',
         'base/cocoa/tracking_area_unittest.mm',
+        'base/dragdrop/os_exchange_data_provider_aurax11_unittest.cc',
         'base/events/event_dispatcher_unittest.cc',
         'base/events/event_unittest.cc',
         'base/gtk/gtk_expanded_container_unittest.cc',
@@ -322,6 +323,11 @@
             'gfx/screen_unittest.cc',
           ],
         }],
+        ['chromeos==1', {
+          'sources!': [
+            'base/dragdrop/os_exchange_data_provider_aurax11_unittest.cc',
+          ],
+        }],
       ],
       'target_conditions': [
         ['OS == "ios"', {