Assert that md5sum was built instead of failing silently.

Assert that md5sum was built instead of failing silently.

The exit when md5sum does not exist fails silently with a short message buried
in the output with no tests run. The reason is because this is an asynchronous
process and the exit does not exist the script. The assert on the other hand
will stop the script and print the following, making it clear the script failed
and that md5sum should be built:

@@@STEP_FAILURE@@@
Traceback (most recent call last):
  File "build/android/run_instrumentation_tests.py", line 108, in <module>
    sys.exit(main(sys.argv))
  File "build/android/run_instrumentation_tests.py", line 101, in main
    ret = DispatchInstrumentationTests(options)
  ...
    results_lists = async_results.get(999999)
  File "/usr/lib/python2.7/multiprocessing/pool.py", line 528, in get
    raise self._value
AssertionError: Please build md5sum.

BUG=


Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=174299

[nyquist, 2012-12-18 03:00:02]

On 2012/12/18 02:53:54, navabi wrote:

lgtm, but someone else more knowledgable about this should look.

One question: Will this have any bad side effects of the script not being able
to clean up, since it now instantly dies?
One note about that is that there is a call to assert right below, so I would
assume it has been tested before.

[Yaron, 2012-12-18 03:13:35]

On 2012/12/18 03:00:02, nyquist wrote:
> On 2012/12/18 02:53:54, navabi wrote:
> 
> lgtm, but someone else more knowledgable about this should look.
> 
> One question: Will this have any bad side effects of the script not being able
> to clean up, since it now instantly dies?
> One note about that is that there is a call to assert right below, so I would
> assume it has been tested before.

I think this solves it more completely:
https://codereview.chromium.org/11597008/

We could still assert that it's built.. but you shouldn't really hit that
scenario anymore

[commit-bot: I haz the power, 2012-12-20 22:51:14]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/navabi@google.com/11613014/1

[commit-bot: I haz the power, 2012-12-21 01:05:56]

Change committed as 174299