Make use of md5_check within write_build_config.py

Make use of md5_check within write_build_config.py

Just for the write_ordered_libraries() part, which is where 95% of the
time is spent.

BUG=533442
Committed: https://crrev.com/c03d57bc86a906986933a906c60e27ec61c04052
Cr-Commit-Position: refs/heads/master@{#350832}

[agrieve, 2015-09-18 15:18:23]

agrieve@chromium.org changed reviewers:
+ pkotwicz@chromium.org

[pkotwicz, 2015-09-18 19:26:49]

pkotwicz@chromium.org changed reviewers:
- pkotwicz@chromium.org

[agrieve, 2015-09-24 19:50:24]

agrieve@chromium.org changed reviewers:
+ pkotwicz@chromium.org

[agrieve, 2015-09-24 19:50:41]

pTaL

[pkotwicz, 2015-09-24 20:32:45]

lgtm

[agrieve, 2015-09-25 02:16:07]

The CQ bit was checked by agrieve@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-09-25 02:16:20]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1350363002/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1350363002/60001

[commit-bot: I haz the power, 2015-09-25 02:40:39]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-09-25 02:40:40]

Dry run: Try jobs failed on following builders:
  android_chromium_gn_compile_rel on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/android_chromiu...)

[agrieve, 2015-09-25 13:53:17]

The CQ bit was checked by agrieve@chromium.org

[agrieve, 2015-09-25 13:53:17]

The patchset sent to the CQ was uploaded after l-g-t-m from
pkotwicz@chromium.org
Link to the patchset: https://codereview.chromium.org/1350363002/#ps80001
(title: "fix empty libs")

[commit-bot: I haz the power, 2015-09-25 13:53:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1350363002/80001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1350363002/80001

[commit-bot: I haz the power, 2015-09-25 15:26:42]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2015-09-25 15:28:21]

Patchset 5 (id:??) landed as
https://crrev.com/c03d57bc86a906986933a906c60e27ec61c04052
Cr-Commit-Position: refs/heads/master@{#350832}