Convert JsonWriter::Write to taking a const ref for the in-param

Convert JsonWriter::Write to taking a const ref for the in-param

Clearer API; flushes out a lot of unnecessary heap allocations.

depends on https://codereview.chromium.org/1129083003/

BUG=none

Committed: https://crrev.com/8d04646294767ea1f3a7da596547b465d50cb4d1
Cr-Commit-Position: refs/heads/master@{#330255}

[Evan Stade, 2015-05-11 20:33:11]

estade@chromium.org changed reviewers:
+ brettw@chromium.org

[Evan Stade, 2015-05-11 20:33:30]

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

[commit-bot: I haz the power, 2015-05-11 20:35:01]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1131113004/20001

[commit-bot: I haz the power, 2015-05-11 21:08:22]

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

[commit-bot: I haz the power, 2015-05-11 21:08:24]

Dry run: Try jobs failed on following builders:
  android_compile_dbg on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/android_compile...)
  ios_rel_device_ninja on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ni...)

[Evan Stade, 2015-05-12 16:40:10]

estade@chromium.org changed reviewers:
+ stevenjb@chromium.org

[Evan Stade, 2015-05-12 16:40:12]

+stevenjb for chromeos stuff

https://codereview.chromium.org/1131113004/diff/40001/remoting/host/setup/dae...
File remoting/host/setup/daemon_controller_delegate_win.cc (left):

https://codereview.chromium.org/1131113004/diff/40001/remoting/host/setup/dae...
remoting/host/setup/daemon_controller_delegate_win.cc:461:
base::JSONWriter::Write(config.release(), &config_str);
caught a leak

[brettw, 2015-05-12 19:10:08]

lgtm

[Evan Stade, 2015-05-12 19:22:19]

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

[commit-bot: I haz the power, 2015-05-12 19:24:35]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1131113004/60001

[commit-bot: I haz the power, 2015-05-12 19:34:32]

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

[commit-bot: I haz the power, 2015-05-12 19:34:34]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[Evan Stade, 2015-05-12 23:40:29]

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

[commit-bot: I haz the power, 2015-05-12 23:40:40]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1131113004/60001

[commit-bot: I haz the power, 2015-05-12 23:50:16]

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

[commit-bot: I haz the power, 2015-05-12 23:50:18]

Dry run: Try jobs failed on following builders:
  linux_chromium_compile_dbg_32_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[stevenjb, 2015-05-15 00:38:15]

owner lgtm

[Evan Stade, 2015-05-15 18:32:34]

The browser tests on linux_chromium_chromeos_asan_rel_ng are flaking with and
without the patch, on this patch and many others. I looked for a while but I'm
95% sure the failures are not related to this patch. Gonna ignore that bot.

[Evan Stade, 2015-05-15 18:33:05]

The CQ bit was checked by estade@chromium.org

[Evan Stade, 2015-05-15 18:33:07]

The patchset sent to the CQ was uploaded after l-g-t-m from brettw@chromium.org,
stevenjb@chromium.org
Link to the patchset: https://codereview.chromium.org/1131113004/#ps160001
(title: "rebase")

[commit-bot: I haz the power, 2015-05-15 18:35:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1131113004/160001

[commit-bot: I haz the power, 2015-05-15 18:57:10]

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

[commit-bot: I haz the power, 2015-05-15 18:57:13]

Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[Evan Stade, 2015-05-15 23:27:38]

The CQ bit was checked by estade@chromium.org

[Evan Stade, 2015-05-15 23:27:39]

The patchset sent to the CQ was uploaded after l-g-t-m from
stevenjb@chromium.org, brettw@chromium.org
Link to the patchset: https://codereview.chromium.org/1131113004/#ps180001
(title: "another rebase")

[commit-bot: I haz the power, 2015-05-15 23:29:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1131113004/180001

[commit-bot: I haz the power, 2015-05-16 01:02:46]

Committed patchset #10 (id:180001)

[commit-bot: I haz the power, 2015-05-18 11:30:19]

Patchset 10 (id:??) landed as
https://crrev.com/8d04646294767ea1f3a7da596547b465d50cb4d1
Cr-Commit-Position: refs/heads/master@{#330255}