Use fake Input Device Settings with chrome://device-emulator

chrome/browser/chromeos/system/fake_input_device_settings.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 CHROME_BROWSER_CHROMEOS_SYSTEM_FAKE_INPUT_DEVICE_SETTINGS_H_
 #define CHROME_BROWSER_CHROMEOS_SYSTEM_FAKE_INPUT_DEVICE_SETTINGS_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "chrome/browser/chromeos/system/input_device_settings.h"
 
 namespace chromeos {
 namespace system {
 
 // This fake just memorizes current values of input devices settings.
-class FakeInputDeviceSettings : public InputDeviceSettings {
+class FakeInputDeviceSettings : public InputDeviceSettings,
+                                public InputDeviceSettings::FakeInterface {
  public:
   FakeInputDeviceSettings();
   ~FakeInputDeviceSettings() override;
 
   // Overridden from InputDeviceSettings.
   void TouchpadExists(const DeviceExistsCallback& callback) override;
   void UpdateTouchpadSettings(const TouchpadSettings& settings) override;
   void SetTouchpadSensitivity(int value) override;
   void SetTapToClick(bool enabled) override;
   void SetThreeFingerClick(bool enabled) override;
   void SetTapDragging(bool enabled) override;
   void MouseExists(const DeviceExistsCallback& callback) override;
   void UpdateMouseSettings(const MouseSettings& settings) override;
   void SetMouseSensitivity(int value) override;
   void SetPrimaryButtonRight(bool right) override;
   void SetNaturalScroll(bool enabled) override;
   void ReapplyTouchpadSettings() override;
   void ReapplyMouseSettings() override;
+  InputDeviceSettings::FakeInterface* GetFakeInterface() override;
 
-  const TouchpadSettings& current_touchpad_settings() const {
-    return current_touchpad_settings_;
-  }
-
-  const MouseSettings& current_mouse_settings() const {
-    return current_mouse_settings_;
-  }
+  // Overridden from InputDeviceSettings::FakeInterface.
+  void set_touchpad_exists(bool exists) override;
+  void set_mouse_exists(bool exists) override;
+  const TouchpadSettings& current_touchpad_settings() const override;
+  const MouseSettings& current_mouse_settings() const override;
 
  private:
   TouchpadSettings current_touchpad_settings_;
   MouseSettings current_mouse_settings_;
 
+  bool touchpad_exists_ = true;
+  bool mouse_exists_ = true;
+
   DISALLOW_COPY_AND_ASSIGN(FakeInputDeviceSettings);
 };
 
 }  // namespace system
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_SYSTEM_FAKE_INPUT_DEVICE_SETTINGS_H_