Li-ion battery maximum discharge current testing
Your charger can only discharge at a maximum of 1 Amp, which for a 3200mAh battery is 1A/3.2Ah = 0.3C. To discharge at 1C you need to draw 3.2A.

Theoretically to get a 1C discharge you need a 3.2A constant current sink, but a resistor that draws ~3.2A on average is close enough. At 3.5V (expected mid-point voltage) the required resistance is 3.5V/3.2A = 1.1&ohm;. But getting exactly 1C isn't vitally important, so 1.0&ohm; or 1.2&ohm; would also do the job.   

The resistor could dissipate up to 15W so it will get hot, and should be a wirewound type rated for 25~30W. If you can't get one that large then wire two or more smaller resistors in parallel or series to get the required values, eg. 2 x 2.2&ohm; 15W in parallel = 1.1&ohm; 30W.

You will need an ammeter which can accurately measure up to 4A with low voltage drop. Most digital multimeters can do 10A, though cheap units may have poor quality leads. Replacing the leads with your own plugs and wiring will help to ensure a good connection.  

To avoid damaging the cell, Stop discharging when the voltage goes below 3V (there is negligible usable capacity remaining after this point). 

To get accurate results you need to record the current at several points during the discharge (eg. one reading per minute), then integrate current x time to get capacity.