[Telemetry] Rename chrome_tracing_agent to chrome_devtools_tracing_agent

[Telemetry] Rename chrome_tracing_agent to chrome_devtools_tracing_agent

This is the first step toward platform-level tracing.

Design doc:
https://docs.google.com/document/d/1Uv8SzOq2ugvzLiOcP85g7qPiaxwsn4tgOdxpe3YjUkM/edit?usp=sharing

BUG=515323
Committed: https://crrev.com/a5597f6cabd7d88393f67a81df9bfe4965d574a3
Cr-Commit-Position: refs/heads/master@{#341174}

[Zhen Wang, 2015-07-30 14:43:41]

zhenw@chromium.org changed reviewers:
+ nednguyen@google.com

[Zhen Wang, 2015-07-30 14:43:42]

ptal

[nednguyen, 2015-07-30 14:59:15]

On 2015/07/30 14:43:42, Zhen Wang wrote:
> ptal

lgtm but can you rename this to chrome_devtools_tracing_agent?

[Zhen Wang, 2015-07-30 17:25:44]

On 2015/07/30 14:59:15, nednguyen wrote:
> On 2015/07/30 14:43:42, Zhen Wang wrote:
> > ptal
> 
> lgtm but can you rename this to chrome_devtools_tracing_agent?

done

[Zhen Wang, 2015-07-30 18:02:47]

The CQ bit was checked by zhenw@chromium.org

[Zhen Wang, 2015-07-30 18:02:48]

The patchset sent to the CQ was uploaded after l-g-t-m from nednguyen@google.com
Link to the patchset: https://codereview.chromium.org/1254383017/#ps20001
(title: " ")

[commit-bot: I haz the power, 2015-07-30 18:02:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1254383017/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1254383017/20001

[commit-bot: I haz the power, 2015-07-30 18:20:22]

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

[commit-bot: I haz the power, 2015-07-30 18:20:23]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Zhen Wang, 2015-07-30 19:28:41]

The CQ bit was checked by zhenw@chromium.org

[commit-bot: I haz the power, 2015-07-30 19:29:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1254383017/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1254383017/20001

[commit-bot: I haz the power, 2015-07-30 19:44:59]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-07-30 19:45:40]

Patchset 2 (id:??) landed as
https://crrev.com/a5597f6cabd7d88393f67a81df9bfe4965d574a3
Cr-Commit-Position: refs/heads/master@{#341174}