x11: Make the event-source work with both glib and libevent message-pumps.

ui/events/events.gyp

Index: ui/events/events.gyp
diff --git a/ui/events/events.gyp b/ui/events/events.gyp
index b74ea75a593913ffb409c39c13ca41294f864963..00f5186c113e982ef979faed938d2b54bd78c02d 100644
--- a/ui/events/events.gyp
+++ b/ui/events/events.gyp
@@ -154,6 +154,8 @@
         'platform/scoped_event_dispatcher.h',
         'platform/x11/x11_event_source.cc',
         'platform/x11/x11_event_source.h',
+        'platform/x11/x11_event_source_glib.cc',
+        'platform/x11/x11_event_source_libevent.cc',
         'win/events_win.cc',
         'x/events_x.cc',
         'linux/text_edit_command_auralinux.cc',
@@ -190,6 +192,14 @@
           'dependencies': [
             '../../build/linux/system.gyp:glib',
           ],
+          'sources!': [
+            'platform/x11/x11_event_source_libevent.cc',
+          ],
+        }, {
+          # use_glib == 0
+          'sources!': [
+            'platform/x11/x11_event_source_glib.cc',
+          ],
         }],
         ['use_ozone_evdev==1', {
           'defines': ['USE_OZONE_EVDEV=1'],