[tracing] Add support for TracedValue JSON serializer.

[tracing] Add support for TracedValue JSON serializer.

BUG=chromium:406277
Committed: https://crrev.com/3990953ba8d9d4674db5caa2278476655e30da1b
Cr-Commit-Position: refs/heads/master@{#40049}

[alph, 2016-10-05 19:22:58]

alph@chromium.org changed reviewers:
+ caseq@chromium.org, fmeawad@chromium.org, jochen@chromium.org,
primiano@chromium.org

[alph, 2016-10-05 19:22:59]

I extracted TracedValue back into a separate patch. Please take a look.

[caseq, 2016-10-05 19:25:59]

lgtm

[alph, 2016-10-05 19:26:25]

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

[commit-bot: I haz the power, 2016-10-05 19:26:36]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[fmeawad, 2016-10-05 19:26:59]

lgtm

[Primiano Tucci (use gerrit), 2016-10-05 19:50:17]

On 2016/10/05 19:26:59, fmeawad wrote:
> lgtm

Not an owner here but LGTM from a tracing planning perspective. 
Thanks and sorry again for the back and forth on this.

[Primiano Tucci (use gerrit), 2016-10-05 19:50:48]

Oops left out comments from my previous msg.

https://codereview.chromium.org/2399463004/diff/1/src/tracing/traced-value.cc
File src/tracing/traced-value.cc (right):

https://codereview.chromium.org/2399463004/diff/1/src/tracing/traced-value.cc...
src/tracing/traced-value.cc:27: std::string result("\"");
maybe you can reserve(length+2) to optimistically reduce the heap traffic for
cases that require no escaping.

https://codereview.chromium.org/2399463004/diff/1/src/tracing/traced-value.cc...
src/tracing/traced-value.cc:31: unsigned char c = value[src];
why unsigned, operator[] is signed IIRC.

[commit-bot: I haz the power, 2016-10-05 20:03:23]

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

[commit-bot: I haz the power, 2016-10-05 20:03:24]

Dry run: This issue passed the CQ dry run.

[alph, 2016-10-06 00:03:11]

https://codereview.chromium.org/2399463004/diff/1/src/tracing/traced-value.cc
File src/tracing/traced-value.cc (right):

https://codereview.chromium.org/2399463004/diff/1/src/tracing/traced-value.cc...
src/tracing/traced-value.cc:27: std::string result("\"");
On 2016/10/05 19:50:48, Primiano Tucci - slow til 10th wrote:
> maybe you can reserve(length+2) to optimistically reduce the heap traffic for
> cases that require no escaping.

Done.

https://codereview.chromium.org/2399463004/diff/1/src/tracing/traced-value.cc...
src/tracing/traced-value.cc:31: unsigned char c = value[src];
On 2016/10/05 19:50:48, Primiano Tucci - slow til 10th wrote:
> why unsigned, operator[] is signed IIRC.

Done.

[jochen (gone - plz use gerrit), 2016-10-06 12:18:27]

lgtm

[alph, 2016-10-06 15:01:28]

The CQ bit was checked by alph@chromium.org

[alph, 2016-10-06 15:01:28]

The patchset sent to the CQ was uploaded after l-g-t-m from
primiano@chromium.org, caseq@chromium.org, fmeawad@chromium.org
Link to the patchset: https://codereview.chromium.org/2399463004/#ps20001
(title: "addressing nits")

[commit-bot: I haz the power, 2016-10-06 15:01:33]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-06 15:27:06]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-10-06 15:27:18]

Description was changed from

==========
[tracing] Add support for TracedValue JSON serializer.

BUG=chromium:406277
==========

to

==========
[tracing] Add support for TracedValue JSON serializer.

BUG=chromium:406277

Committed: https://crrev.com/3990953ba8d9d4674db5caa2278476655e30da1b
Cr-Commit-Position: refs/heads/master@{#40049}
==========

[commit-bot: I haz the power, 2016-10-06 15:27:20]

Patchset 2 (id:??) landed as
https://crrev.com/3990953ba8d9d4674db5caa2278476655e30da1b
Cr-Commit-Position: refs/heads/master@{#40049}