Merge changes Iff1ec14b,I32123c51,I517dbcba,Ic215c7fe

* changes:
  adb: try harder to fill our test sockets.
  adb: don't set has_write_error on success.
  adb: move ownership of the fdevent thread into FdeventTest.
  adb: guarantee that fdevent_run_on_main_thread happens last.