Adjust callers and networking delegates in ios/ to modified APIs

Use modified Read and delegate methods from the following CL-
https://codereview.chromium.org/2262653003/

BUG=423484

Committed: https://crrev.com/5af9098dfe78b06569f9007caa84349beca417df
Review-Url: https://codereview.chromium.org/2262063002
Cr-Original-Commit-Position: refs/heads/master@{#416528}
Cr-Commit-Position: refs/heads/master@{#416584}
1 file changed