[remoting][FTL] Add unittest for FtlSignalStrategy

This CL adds unittest for the FtlSignalStrategy class.

Bug: 965746
Change-Id: I2bd55e067c455d6aae05151393228c8044c9a550
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1623494
Commit-Queue: Yuwei Huang <yuweih@chromium.org>
Reviewed-by: Joe Downing <joedow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662362}
11 files changed