Add display task to trigger display configuration

ui/display/chromeos/test/test_native_display_delegate.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_DISPLAY_CHROMEOS_TEST_TEST_NATIVE_DISPLAY_DELEGATE_H_
 #define UI_DISPLAY_CHROMEOS_TEST_TEST_NATIVE_DISPLAY_DELEGATE_H_
 
 #include <vector>
 
 #include "base/macros.h"
@@ skipping 31 matching lines @@
   // NativeDisplayDelegate overrides:
   void Initialize() override;
   void GrabServer() override;
   void UngrabServer() override;
   bool TakeDisplayControl() override;
   bool RelinquishDisplayControl() override;
   void SyncWithServer() override;
   void SetBackgroundColor(uint32_t color_argb) override;
   void ForceDPMSOn() override;
   std::vector<DisplaySnapshot*> GetDisplays() override;
+  void GetDisplays(const GetDisplaysCallback& callback) override;
   void AddMode(const DisplaySnapshot& output, const DisplayMode* mode) override;
   bool Configure(const DisplaySnapshot& output,
                  const DisplayMode* mode,
                  const gfx::Point& origin) override;
   void Configure(const DisplaySnapshot& output,
                  const DisplayMode* mode,
                  const gfx::Point& origin,
                  const ConfigureCallback& callback) override;
   void CreateFrameBuffer(const gfx::Size& size) override;
   bool GetHDCPState(const DisplaySnapshot& output, HDCPState* state) override;
@@ skipping 26 matching lines @@
 
   ActionLogger* log_;  // Not owned.
 
   DISALLOW_COPY_AND_ASSIGN(TestNativeDisplayDelegate);
 };
 
 }  // namespace test
 }  // namespace ui
 
 #endif  // UI_DISPLAY_CHROMEOS_TEST_TEST_NATIVE_DISPLAY_DELEGATE_H_