Remove superfluous AsyncTask

PlatformNetworksManager.computeVisibleNetworks was switched to accepting
a callback for async executition of the expensive call to
TelephonyManager, but was still posted to an AsyncTask. Clean up
unnecessary background task wrapper.

Bug: 955560
Change-Id: I1ec8c27ff2c0fae65cec97902279d196c8f68cf8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1628810
Reviewed-by: Yusuf Ozuysal <yusufo@chromium.org>
Commit-Queue: Natalie Chouinard <chouinard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663246}
1 file changed