Add tests for InputDeviceServer/InputDeviceClient.

services/ui/public/cpp/input_devices/input_device_client.h

Index: services/ui/public/cpp/input_devices/input_device_client.h
diff --git a/services/ui/public/cpp/input_devices/input_device_client.h b/services/ui/public/cpp/input_devices/input_device_client.h
index 54e578d7c53957d015b1e18d266c81331352061f..50a9fa1fb98463b690d3c81c2175cb7e9ce84ca1 100644
--- a/services/ui/public/cpp/input_devices/input_device_client.h
+++ b/services/ui/public/cpp/input_devices/input_device_client.h
@@ -47,7 +47,12 @@ class InputDeviceClient : public mojom::InputDeviceObserverMojo,
   void AddObserver(ui::InputDeviceEventObserver* observer) override;
   void RemoveObserver(ui::InputDeviceEventObserver* observer) override;
 
- private:
+ protected:
+  // Default constructor registers as InputDeviceManager. Can be subclassed in
+  // tests to avoid this.
+  explicit InputDeviceClient(bool is_input_device_manager);
+  mojom::InputDeviceObserverMojoPtr GetIntefacePtr();
+
   // mojom::InputDeviceObserverMojo:
   void OnKeyboardDeviceConfigurationChanged(
       const std::vector<ui::InputDevice>& devices) override;
@@ -63,8 +68,11 @@ class InputDeviceClient : public mojom::InputDeviceObserverMojo,
       const std::vector<ui::InputDevice>& mouse_devices,
       const std::vector<ui::InputDevice>& touchpad_devices) override;
 
+ private:
   mojo::Binding<mojom::InputDeviceObserverMojo> binding_;
 
+  bool is_input_device_manager_;
+
   // Holds the list of input devices and signal that we have received the lists
   // after initialization.
   std::vector<ui::InputDevice> keyboard_devices_;