Use DictionaryBuilder in printer_provider_apitest.cc.

Use DictionaryBuilder in printer_provider_apitest.cc.

JSON string literals are hard to work with because of all the escaping
necessary. The DictionaryBuilder class makes it easy to construct a
base::Value with code.

Committed: https://crrev.com/41c7c99738922ce2ecb88445c8a34716e1e0c9ad
Cr-Commit-Position: refs/heads/master@{#329716}

[Reilly Grant (use Gerrit), 2015-05-13 20:38:00]

reillyg@chromium.org changed reviewers:
+ tbarzic@chromium.org

[Reilly Grant (use Gerrit), 2015-05-13 20:38:02]

Please take a look at this cleanup patch. I was working on adding new tests and
all the escaped quotation marks started to get to me.

[tbarzic, 2015-05-13 20:40:35]

lgtm

[Reilly Grant (use Gerrit), 2015-05-13 20:47:32]

The CQ bit was checked by reillyg@chromium.org

[commit-bot: I haz the power, 2015-05-13 20:48:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1138013006/1

[commit-bot: I haz the power, 2015-05-13 21:12:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-13 21:13:11]

Patchset 1 (id:??) landed as
https://crrev.com/41c7c99738922ce2ecb88445c8a34716e1e0c9ad
Cr-Commit-Position: refs/heads/master@{#329716}