[CRD iOS] Translate "\n" into an enter keypress

iOS is sending a "\n" unicode text event to the host when the user taps
the `return` key. On Windows this doesn't always generate a newline.

This CL fixes this issue by translating the "\n" text event into a
ENTER keypress before sending it to the host.

Bug: 830959
Change-Id: Ib94caf6ce2036cc5654f1b59f1e0136c81c9eec1
Reviewed-on: https://chromium-review.googlesource.com/1003598
Commit-Queue: Yuwei Huang <yuweih@chromium.org>
Reviewed-by: Jamie Walch <jamiewalch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#549385}
5 files changed