Add FakeDisplayDelegate for off device usage.

ui/display/types/fake_display_controller.h

+// 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_DISPLAY_TYPES_FAKE_DISPLAY_CONTROLLER_H_
+#define UI_DISPLAY_TYPES_FAKE_DISPLAY_CONTROLLER_H_
+
+#include <stdint.h>
+
+#include "ui/display/types/display_types_export.h"
+
+namespace gfx {
+class Size;
+}
+
+namespace display {
+
+// Controls the fake display state. Provided by the NativeDisplayDelegate if
+// it is intended for use off device where there are no physical displays and
+// we need to fake the display state.
+class DISPLAY_TYPES_EXPORT FakeDisplayController {
+ public:
+  // Adds a fake display with the specified size, returns the display id or
+  // |kInvalidDisplayId| if it fails.
+  virtual int64_t AddDisplay(const gfx::Size& display_size) = 0;
+
+  // Removes a fake display with specified id, returns true if successful.
+  virtual bool RemoveDisplay(int64_t display_id) = 0;
+
+ protected:
+  virtual ~FakeDisplayController() {}
+};
+
+}  // namespace display
+
+#endif  // UI_DISPLAY_TYPES_FAKE_DISPLAY_CONTROLLER_H_