Fix out of order key events in Chrome on Linux.

ui/events/platform/x11/x11_event_source.h

 // Copyright 2014 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.
 
 #ifndef UI_EVENTS_PLATFORM_X11_X11_EVENT_SOURCE_H_
 #define UI_EVENTS_PLATFORM_X11_X11_EVENT_SOURCE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 46 matching lines @@
   //
   // For those that know X11, this is really a wrapper around XWindowEvent
   // which still makes sure the preempted event is dispatched instead of
   // dropped on the floor. This method exists because mapping a window is
   // asynchronous (and we receive an XEvent when mapped), while there are also
   // functions which require a mapped window.
   void BlockUntilWindowMapped(XID window);
 
   void BlockUntilWindowUnmapped(XID window);
 
+  // Dispatches a given event immediately. This is to faciliate sequential
+  // interaction between the gtk event loop (used for IME) and the
+  // main X11 event loop.
+  void DispatchEventNow(XEvent* event);

[Yuki, 2016/08/16 09:26:11]

nit: We should declare this member function between DispatchXEvents and
BlockUntilWindowMapped.

nit: s/DispatchEventNow/DispatchXEventNow/ because we already have
DispatchXEvents.

[dtapuska, 2016/08/16 14:48:29]

Done.

+
   XDisplay* display() { return display_; }
   Time last_seen_server_time() const { return last_seen_server_time_; }
 
   // Explicitly asks the X11 server for the current timestamp, and updates
   // |last_seen_server_time| with this value.
   Time UpdateLastSeenServerTime();
 
   void StopCurrentEventStream();
   void OnDispatcherListChanged();
 
@@ skipping 31 matching lines @@
   bool continue_stream_ = true;
 
   std::unique_ptr<X11HotplugEventHandler> hotplug_event_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(X11EventSource);
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_PLATFORM_X11_X11_EVENT_SOURCE_H_