Revert of Android: support multiple displays on C++ side

ui/android/dummy_screen_android.h

Index: ui/android/dummy_screen_android.h
diff --git a/ui/android/dummy_screen_android.h b/ui/android/dummy_screen_android.h
deleted file mode 100644
index 3e61475e9d0a894e178e4d78ebba48497df20cbb..0000000000000000000000000000000000000000
--- a/ui/android/dummy_screen_android.h
+++ /dev/null
@@ -1,22 +0,0 @@
-// Copyright 2016 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_ANDROID_SCREEN_DUMMY_SCREEN_ANDROID_H_
-#define UI_ANDROID_SCREEN_DUMMY_SCREEN_ANDROID_H_
-
-#include "ui/android/ui_android_export.h"
-
-namespace display {
-class Screen;
-}
-
-namespace ui {
-
-// Creates Screen containing one dummy Display that does not
-// communicate with Java layer.
-UI_ANDROID_EXPORT display::Screen* CreateDummyScreenAndroid();
-
-}  // namespace display
-
-#endif  // UI_ANDROID_SCREEN_DUMMY_SCREEN_ANDROID_H_