On Android, the JNI jobject type doesn't always contain a pointer. Treating a non-pointer as a pointer can crash the runtime. Use the more appropriate type uintptr instead. Change-Id: I2b2049918d60226c4d23d6df0b10e68248d54bc2 Reviewed-on: https://go-review.googlesource.com/110256 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>