[devtools] Resynchronize loadNetworkResource implementation..

..between browser and shell bindings. The interface has gotten out of
sync after crrev.com/c/1951104 which introduced additional error
reporting.

TBR=yangguo@chromium.org

Bug: chromium:1030746
Change-Id: If609eb709156e3d0b2142e631878c8821fc1f84c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2000622
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732383}
2 files changed