ozone: dri: Fix undefined references in DRI platform GN build

ui/ozone/platform/dri/dri_window_delegate_impl.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_OZONE_PLATFORM_DRI_DRI_WINDOW_DELEGATE_IMPL_H_
 #define UI_OZONE_PLATFORM_DRI_DRI_WINDOW_DELEGATE_IMPL_H_
 
 #include "base/timer/timer.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/native_widget_types.h"
+#include "ui/ozone/ozone_export.h"
 #include "ui/ozone/platform/dri/display_change_observer.h"
 #include "ui/ozone/platform/dri/dri_window_delegate.h"
 
 namespace ui {
 
 class DriBuffer;
 class DriWindowDelegateManager;
 class DriWrapper;
 class HardwareDisplayController;
 class ScreenManager;
 
-class DriWindowDelegateImpl : public DriWindowDelegate,
-                              public DisplayChangeObserver {
+class OZONE_EXPORT DriWindowDelegateImpl : public DriWindowDelegate,
+                                           public DisplayChangeObserver {
  public:
   DriWindowDelegateImpl(gfx::AcceleratedWidget widget,
                         DriWrapper* drm,
                         DriWindowDelegateManager* window_manager,
                         ScreenManager* screen_manager);
   ~DriWindowDelegateImpl() override;
 
   // DriWindowDelegate:
   void Initialize() override;
   void Shutdown() override;
@@ skipping 40 matching lines @@
   gfx::Point cursor_location_;
   int cursor_frame_;
   int cursor_frame_delay_ms_;
 
   DISALLOW_COPY_AND_ASSIGN(DriWindowDelegateImpl);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_DRI_DRI_WINDOW_DELEGATE_IMPL_H_