Fix building of bwe_test_logging.cc in gyp and gn builds

Fix building of bwe_test_logging.cc in gyp and gn builds

bwe_test_logging.cc is supposed to be conditionally built in gyp builds
but, due to a path error in the sources! expressions it was always
compiled.

Meanwhile, compilation of bwe_test_logging.cc was never set up for gn
builds.

This fixes both of these problems.

BUG=604060
Committed: https://crrev.com/07df20b51ab50078263f43a9a516b7ac7130d42e
Cr-Commit-Position: refs/heads/master@{#12842}

[brucedawson, 2016-05-19 19:03:15]

brucedawson@chromium.org changed reviewers:
+ stefan@webrtc.org

[brucedawson, 2016-05-19 19:03:17]

PTAL. I think this corrects the .gyp and .gn files to match the intent but
confirmation would be appreciated. I've confirmed that this lets me
conditionally add bwe_test_logging.cc to the gn builds, and by default it
removes that file from gyp builds.

[stefan-webrtc, 2016-05-22 23:14:07]

Looks correct. lgtm

[stefan-webrtc, 2016-05-22 23:14:15]

The CQ bit was checked by stefan@webrtc.org

[commit-bot: I haz the power, 2016-05-22 23:14:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1990373002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1990373002/1

[commit-bot: I haz the power, 2016-05-23 00:15:07]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-23 00:15:15]

Description was changed from

==========
Fix building of bwe_test_logging.cc in gyp and gn builds

bwe_test_logging.cc is supposed to be conditionally built in gyp builds
but, due to a path error in the sources! expressions it was always
compiled.

Meanwhile, compilation of bwe_test_logging.cc was never set up for gn
builds.

This fixes both of these problems.

BUG=604060
==========

to

==========
Fix building of bwe_test_logging.cc in gyp and gn builds

bwe_test_logging.cc is supposed to be conditionally built in gyp builds
but, due to a path error in the sources! expressions it was always
compiled.

Meanwhile, compilation of bwe_test_logging.cc was never set up for gn
builds.

This fixes both of these problems.

BUG=604060

Committed: https://crrev.com/07df20b51ab50078263f43a9a516b7ac7130d42e
Cr-Commit-Position: refs/heads/master@{#12842}
==========

[commit-bot: I haz the power, 2016-05-23 00:15:16]

Patchset 1 (id:??) landed as
https://crrev.com/07df20b51ab50078263f43a9a516b7ac7130d42e
Cr-Commit-Position: refs/heads/master@{#12842}