Let adb_gdb support privileged processes with a switch.

Add "--privileged" and "--privileged=<num>" that works similar to
"--sandboxed" to make it easier to debug the GPU process on Android.

BUG=468697

Review URL: https://codereview.chromium.org/1023703002

Cr-Commit-Position: refs/heads/master@{#321351}
1 file changed