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"
@@ skipping 15 matching lines @@
   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;
 
+  void SetMouseExists(bool exists);
+  void SetTouchpadExists(bool exists);

[stevenjb, 2016/06/30 00:17:30]

Inline these and name them set_mouse_exists, etc.

[michaelpg, 2016/07/01 22:01:48]

Done.

+
   const TouchpadSettings& current_touchpad_settings() const {
     return current_touchpad_settings_;
   }
 
   const MouseSettings& current_mouse_settings() const {
     return current_mouse_settings_;
   }
 
  private:
   TouchpadSettings current_touchpad_settings_;
   MouseSettings current_mouse_settings_;
 
+  bool mouse_exists_;
+  bool touchpad_exists_;
+
   DISALLOW_COPY_AND_ASSIGN(FakeInputDeviceSettings);
 };
 
 }  // namespace system
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_SYSTEM_FAKE_INPUT_DEVICE_SETTINGS_H_