CompressedStringDataSink for trace_controller.

Added a new CompressedStringDataSink for compressing traces via the trace controller.

Also added a TraceDataEndpoint class that I'm thinking can be used to decouple the creation of the final trace (since there's some special logic in there for adding '{}'s and some specific names like 'traceEvent') from where it gets written. This is used right now by the new BackgroundTracingManager for Slow Reports and Deep Reports, but we could also refactor the existing String and File sinks this way as a follow up CL (WIP here: https://codereview.chromium.org/1002103004/).

Then for Deep Reports we can specify the data sink like so:

TraceController::DisableRecording(
  TraceController::CreateCompressedStringSink(
    TraceController::CreateFileEndpoint(...)));

Committed: https://crrev.com/329f14fe8729f500bad122cafba31ff075b788dd
Cr-Commit-Position: refs/heads/master@{#326783}

[shatch, 2015-04-14 20:20:10]

Patchset #1 (id:1) has been deleted

[shatch, 2015-04-14 20:20:17]

Patchset #1 (id:20001) has been deleted

[shatch, 2015-04-16 18:49:57]

simonhatch@chromium.org changed reviewers:
+ dsinclair@chromium.org, nduca@chromium.org

[shatch, 2015-04-16 18:53:54]

Patchset #2 (id:60001) has been deleted

[shatch, 2015-04-16 18:53:59]

Patchset #1 (id:40001) has been deleted

[shatch, 2015-04-16 19:10:35]

Patchset #1 (id:80001) has been deleted

[shatch, 2015-04-16 19:30:54]

simonhatch@chromium.org changed reviewers:
- dsinclair@chromium.org

[shatch, 2015-04-16 19:33:07]

Patchset #1 (id:100001) has been deleted

[shatch, 2015-04-16 19:36:56]

Hey Nat, added compression in the trace controller, ptal

[nduca, 2015-04-21 17:10:20]

seems cool but this is getting big enough maybe time to put it in its own file?

[nduca, 2015-04-21 17:11:07]

actually lgtm maybe have dan give you a local-timezone final review once you've
pulled it out to a fresh file?

[shatch, 2015-04-21 19:18:17]

simonhatch@chromium.org changed reviewers:
+ dsinclair@chromium.org

[shatch, 2015-04-21 19:18:34]

+dsinclair

ptal!

[dsinclair, 2015-04-21 19:21:22]

lgtm. If there is no bug, remove the BUG= line.

[shatch, 2015-04-21 19:29:24]

simonhatch@chromium.org changed reviewers:
+ sievers@chromium.org

[shatch, 2015-04-21 19:32:06]

+sievers

Hi Daniel, can I get a stamp for content/public/browser/tracing_controller.h?

[no sievers, 2015-04-22 21:35:19]

On 2015/04/21 19:32:06, shatch wrote:
> +sievers
> 
> Hi Daniel, can I get a stamp for content/public/browser/tracing_controller.h?

lgtm

[shatch, 2015-04-23 16:42:13]

The CQ bit was checked by simonhatch@chromium.org

[shatch, 2015-04-23 16:42:13]

The patchset sent to the CQ was uploaded after l-g-t-m from nduca@chromium.org
Link to the patchset: https://codereview.chromium.org/1088673003/#ps150004
(title: "Moved to new file.")

[commit-bot: I haz the power, 2015-04-23 16:42:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1088673003/150004

[commit-bot: I haz the power, 2015-04-23 17:30:09]

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

[commit-bot: I haz the power, 2015-04-23 17:30:10]

Try jobs failed on following builders:
  linux_chromium_chromeos_ozone_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[shatch, 2015-04-23 20:40:20]

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

[shatch, 2015-04-23 20:40:20]

The patchset sent to the CQ was uploaded after l-g-t-m from
dsinclair@chromium.org, nduca@chromium.org, sievers@chromium.org
Link to the patchset: https://codereview.chromium.org/1088673003/#ps170001
(title: "Fix win compile and tests.")

[commit-bot: I haz the power, 2015-04-23 20:40:41]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1088673003/170001

[commit-bot: I haz the power, 2015-04-23 21:45:23]

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

[commit-bot: I haz the power, 2015-04-23 21:45:26]

Dry run: This issue passed the CQ dry run.

[shatch, 2015-04-24 13:41:25]

The CQ bit was checked by simonhatch@chromium.org

[commit-bot: I haz the power, 2015-04-24 13:41:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1088673003/170001

[commit-bot: I haz the power, 2015-04-24 13:42:32]

Committed patchset #4 (id:170001)

[commit-bot: I haz the power, 2015-04-24 13:43:42]

Patchset 4 (id:??) landed as
https://crrev.com/329f14fe8729f500bad122cafba31ff075b788dd
Cr-Commit-Position: refs/heads/master@{#326783}