Add FakeDisplaySnapshot builder and related changes.

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 <memory>
+
 #include "ui/display/types/display_types_export.h"
 
 namespace gfx {
 class Size;
 }
 
+namespace ui {
+class DisplaySnapshot;
+}
+
 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;
 
+  // Adds |display| to the list of displays and returns true if successful. Will
+  // fail if an existing display has the same id as |display|.
+  virtual bool AddDisplay(std::unique_ptr<ui::DisplaySnapshot> display) = 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_