x11: Move XInput2 availability information out of the message pump.

ui/events/events.gyp

Index: ui/events/events.gyp
diff --git a/ui/events/events.gyp b/ui/events/events.gyp
index 6684622efa701f324e2561479f400c10c2d1cde4..8744a6a78e2f197d6b8acc19fae32e49073eedd7 100644
--- a/ui/events/events.gyp
+++ b/ui/events/events.gyp
@@ -12,7 +12,8 @@
       'type': '<(component)',
       'dependencies': [
         '<(DEPTH)/base/base.gyp:base',
-        ],
+        '<(DEPTH)/base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
+      ],
       'defines': [
         'EVENTS_BASE_IMPLEMENTATION',
       ],
@@ -35,6 +36,19 @@
         'keycodes/keyboard_codes.h',
         'latency_info.cc',
         'latency_info.h',
+        'x/device_list_cache_x.cc',
+        'x/device_list_cache_x.h',
+        'x/device_data_manager.cc',
+        'x/device_data_manager.h',
+        'x/touch_factory_x11.cc',
+        'x/touch_factory_x11.h',
+      ],
+      'conditions': [
+        ['use_x11==1', {
+          'dependencies': [
+            '<(DEPTH)/build/linux/system.gyp:x11',
+          ],
+        }],
       ],
     },
     {
@@ -93,15 +107,9 @@
         'ozone/event_factory_ozone.h',
         'ozone/events_ozone.cc',
         'win/events_win.cc',
-        'x/device_data_manager.cc',
-        'x/device_data_manager.h',
-        'x/device_list_cache_x.cc',
-        'x/device_list_cache_x.h',
         'x/events_x.cc',
         'x/events_x_utils.cc',
         'x/events_x_utils.h',
-        'x/touch_factory_x11.cc',
-        'x/touch_factory_x11.h',
       ],
       'conditions': [
         # We explicitly enumerate the platforms we _do_ provide native cracking