Remove GetPlatformDefaultEGLNativeDisplay() function.

ui/gl/gl_surface_egl_x11.cc

 // Copyright (c) 2015 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.
 
 #include "ui/gl/gl_surface_egl_x11.h"
 
 #include "ui/events/platform/platform_event_source.h"
-#include "ui/gfx/x/x11_types.h"
 #include "ui/gl/egl_util.h"
 
 extern "C" {
 #include <X11/Xlib.h>
 }
 
 using ui::GetLastEGLErrorString;
 using ui::PlatformEvent;
 using ui::PlatformEventSource;
 
@@ skipping 152 matching lines @@
   Display* x11_display = GetNativeDisplay();
   XSendEvent(x11_display, parent_window_, False, ExposureMask, &x_event);
   XFlush(x11_display);
   return ui::POST_DISPATCH_STOP_PROPAGATION;
 }
 
 NativeViewGLSurfaceEGLX11::~NativeViewGLSurfaceEGLX11() {
   Destroy();
 }
 
-EGLNativeDisplayType GetPlatformDefaultEGLNativeDisplay() {
-  return gfx::GetXDisplay();
-}
-
 }  // namespace gl