Code review comment for lp:~andreas-pokorny/mir/move-input-report

lgtm,
nit:
79 + void open_input_device(char const* device_name, char const* input_platform) override;
80 + void failure_opening_input_device(char const* device_name, char const* input_platform) override;

opened_input_device(...), failed_to_open_input_device(...)
make it clearer that we are reporting something that happened in the past, as opposed to trying to open an input device from the function.