Cleanup display creation in mus tests.

services/ui/ws/platform_display_default.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 SERVICES_UI_WS_PLATFORM_DISPLAY_DEFAULT_H_
 #define SERVICES_UI_WS_PLATFORM_DISPLAY_DEFAULT_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 26 matching lines @@
   void SetViewportSize(const gfx::Size& size) override;
   void SetTitle(const base::string16& title) override;
   void SetCapture() override;
   void ReleaseCapture() override;
   void SetCursorById(mojom::Cursor cursor) override;
   void UpdateTextInputState(const ui::TextInputState& state) override;
   void SetImeVisibility(bool visible) override;
   gfx::Rect GetBounds() const override;
   bool UpdateViewportMetrics(const display::ViewportMetrics& metrics) override;
   const display::ViewportMetrics& GetViewportMetrics() const override;
-  bool IsPrimaryDisplay() const override;
   void OnGpuChannelEstablished(
       scoped_refptr<gpu::GpuChannelHost> gpu_channel) override;
 
  private:
   // Update the root_location of located events to be relative to the origin
   // of this display. For example, if the origin of this display is (1800, 0)
   // and the location of the event is (100, 200) then the root_location will be
   // updated to be (1900, 200).
   // TODO(riajiang): This is totally broken with HDPI.
   void UpdateEventRootLocation(ui::LocatedEvent* event);
 
   // ui::PlatformWindowDelegate:
   void OnBoundsChanged(const gfx::Rect& new_bounds) override;
   void OnDamageRect(const gfx::Rect& damaged_region) override;
   void DispatchEvent(ui::Event* event) override;
   void OnCloseRequest() override;
   void OnClosed() override;
   void OnWindowStateChanged(ui::PlatformWindowState new_state) override;
   void OnLostCapture() override;
   void OnAcceleratedWidgetAvailable(gfx::AcceleratedWidget widget,
                                     float device_scale_factor) override;
   void OnAcceleratedWidgetDestroyed() override;
   void OnActivationChanged(bool active) override;
 
   // FrameGeneratorDelegate:
   bool IsInHighContrastMode() override;
 
-  int64_t display_id_;
+  const int64_t display_id_;
 
 #if !defined(OS_ANDROID)
   std::unique_ptr<ui::CursorLoader> cursor_loader_;
 #endif
 
   PlatformDisplayDelegate* delegate_ = nullptr;
   std::unique_ptr<FrameGenerator> frame_generator_;
 
   display::ViewportMetrics metrics_;
   std::unique_ptr<ui::PlatformWindow> platform_window_;
 
   DISALLOW_COPY_AND_ASSIGN(PlatformDisplayDefault);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_PLATFORM_DISPLAY_DEFAULT_H_