Start using JniIntWrapper from Chromium instead of bypassing it in jni_generator_helper.h. Bug: webrtc:8278 Change-Id: I20313e1e610b05f79c210e823ab50cfb2073674e Reviewed-on: https://webrtc-review.googlesource.com/74841 Reviewed-by: Sami Kalliomäki <sakal@webrtc.org> Commit-Queue: Magnus Jedvert <magjed@webrtc.org> Cr-Commit-Position: refs/heads/master@{#23230}