[wpimath] FromFieldRelativeSpeeds: Add ChassisSpeeds overload (#4494)

wpimath/src/main/native/include/frc/kinematics/ChassisSpeeds.h

@@ -60,5 +60,26 @@ struct WPILIB_DLLEXPORT ChassisSpeeds {
     return {vx * robotAngle.Cos() + vy * robotAngle.Sin(),
             -vx * robotAngle.Sin() + vy * robotAngle.Cos(), omega};
   }
+
+  /**
+   * Converts a user provided field-relative ChassisSpeeds object into a
+   * robot-relative ChassisSpeeds object.
+   *
+   * @param fieldRelativeSpeeds The ChassisSpeeds object representing the speeds
+   *    in the field frame of reference. Positive x is away from your alliance
+   *    wall. Positive y is to your left when standing behind the alliance wall.
+   * @param robotAngle The angle of the robot as measured by a gyroscope. The
+   *    robot's angle is considered to be zero when it is facing directly away
+   *    from your alliance station wall. Remember that this should be CCW
+   *    positive.
+   * @return ChassisSpeeds object representing the speeds in the robot's frame
+   *    of reference.
+   */
+  static ChassisSpeeds FromFieldRelativeSpeeds(
+      const ChassisSpeeds& fieldRelativeSpeeds, const Rotation2d& robotAngle) {
+    return FromFieldRelativeSpeeds(fieldRelativeSpeeds.vx,
+                                   fieldRelativeSpeeds.vy,
+                                   fieldRelativeSpeeds.omega, robotAngle);
+  }
 };
 }  // namespace frc