1. A construction machine comprising: a prime mover; a tank that stores a hydraulic fluid; a one-sided tilting variable displacement first hydraulic pump that is driven by the prime mover and that delivers the hydraulic fluid drawn from the tank; a plurality of hydraulic actuators that are driven by the hydraulic fluid supplied from the first hydraulic pump; an operation device that gives an instruction for operations of the plurality of hydraulic actuators; and a controller that controls a revolution speed of the prime mover and tilting of the first hydraulic pump, wherein the construction machine further comprises a first pressure sensor that detects a pressure of the first hydraulic pump, a first bleed-off adjusting device that is enabled to adjust a bleed-off flow rate of the first hydraulic pump, and an input device that gives an instruction for measurement of a leakage flow rate of the first hydraulic pump, and the controller is connected to the operation device, the first pressure sensor, the first bleed-off adjusting device, and the input device, and is programmed to determine an operated state of the operation device on a basis of an input signal from the operation device, convert a detected signal from the first pressure sensor into a pressure value, and output a control signal based on a control command value to the first bleed-off adjusting device, and is configured to, in a case where the controller determines that the operation device is in a non-operated state and where a measuring command is inputted from the input device, measure a pressure of the first hydraulic pump while changing the control command value for the first bleed-off adjusting device in a state in which a flow rate of the first hydraulic pump is maintained, and calculate the leakage flow rate of the first hydraulic pump on a basis of the control command value for the first bleed-off adjusting device at a time that the pressure of the first hydraulic pump is stabilized at a predetermined pressure.