Use ssh to trigger chromecast test

Using adb seemed to ignore errors in some cases, primarily
if nanobench crashed/hung.

Bug: skia:6706
Change-Id: I5def49d5b4d20bed6c486b7e85040190be856ac8
Reviewed-on: https://skia-review.googlesource.com/18404
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Eric Boren <borenet@google.com>
5 files changed