Remove unnecessary #ifdef case.

Remove #ifdef USE_X11 && !USE_GLIB check. That would have been for the
X11 CrOS build which no longer exists.

Bug: none
Change-Id: Iccea3d36ef92ed1dde44773ce4a74184a7a2c37b
Reviewed-on: https://chromium-review.googlesource.com/1014281Reviewed-by: Gabriel Charette <gab@chromium.org>
Commit-Queue: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551801}

base/message_loop/message_loop_current.cc

@@ -157,8 +157,7 @@ bool MessageLoopCurrentForUI::IsSet() {
 #endif  // defined(OS_ANDROID)
 }
 
-#if (defined(USE_OZONE) && !defined(OS_FUCHSIA)) || \
-    (defined(USE_X11) && !defined(USE_GLIB))
+#if defined(USE_OZONE) && !defined(OS_FUCHSIA)
 bool MessageLoopCurrentForUI::WatchFileDescriptor(
     int fd,
     bool persistent,

base/message_loop/message_loop_current.h

@@ -215,8 +215,7 @@ class BASE_EXPORT MessageLoopCurrentForUI : public MessageLoopCurrent {
 
   MessageLoopCurrentForUI* operator->() { return this; }
 
-#if (defined(USE_OZONE) && !defined(OS_FUCHSIA)) || \
-    (defined(USE_X11) && !defined(USE_GLIB))
+#if defined(USE_OZONE) && !defined(OS_FUCHSIA)
   // Please see MessagePumpLibevent for definition.
   static_assert(std::is_same<MessagePumpForUI, MessagePumpLibevent>::value,
                 "MessageLoopCurrentForUI::WatchFileDescriptor is not supported "