A poor man's release-time assert for failing to open the test data file.

A poor man's release-time assert for failing to open the test data file.

This patch prevents running unit tests from an incorrect directory in
release mode. Release mode builds ignore assert(file.is_open()) for the
test data file, which causes many hard-to-diagnose crashes due to the
rest of the code relying on that file being open. See
http://crbug.com/395169 and http://crbug.com/396203 for examples.

R=roubert@google.com

Committed: https://code.google.com/p/libaddressinput/source/detail?r=316

[Rouslan Solomakhin, 2014-07-23 18:35:22]

Fredrik: PTAL.

[roubert (google), 2014-07-23 19:16:41]

LGTM

This is a good example of why I don't think that it generally is a good idea to
remove assertions in release builds ... In the future, we might want to have our
own assertion implementation for use in the libaddressinput test code, that
never gets "optimized" away.

[Rouslan Solomakhin, 2014-07-23 19:52:06]

Committed patchset #1 manually as r316 (presubmit successful).