commit a3e9592cafd53d5ecf95621d907e7c0f57825fae
author Ang Li <angli@google.com> Tue Apr 19 16:31:49 2016 -0700
committer Ang Li <angli@google.com> Tue Apr 19 17:56:10 2016 -0700
tree 593c60846236c4c380afc79b3a38d01bb55c9234
parent d6e3403250743c8941456eda96055acdea47458c

Handle exceptions in procedure functions properly.

Bug=26968438

Tests should not be considered pass if exceptions happened in post-
test funtions like on_pass, on_skip etc.

A new field in test record is added to hold extra errors. More than
one error may occur in a test process since errors can happen during
procedure functions.

Override __str__ function in TestSignal to include all fields.

Change-Id: Ie1d6837e815c4840599088f9ad01bb9a35495668