Revert of Remove support for GlobalNetworkClientFactory from RequestTracker.

Revert of Remove support for GlobalNetworkClientFactory from RequestTracker. (patchset #1 id:1 of https://codereview.chromium.org/2633453004/ )

Reason for revert:
Base CL breaks CroNet: https://codereview.chromium.org/2627973005

Original issue's description:
> Remove support for GlobalNetworkClientFactory from RequestTracker.
> 
> The method RequestTracker::AddGlobalNetworkClientFactory is never
> called so remove the method and the support code.
> 
> BUG=585700
> 
> Review-Url: https://codereview.chromium.org/2633453004
> Cr-Commit-Position: refs/heads/master@{#443591}
> Committed: https://chromium.googlesource.com/chromium/src/+/12bd970214af9f7a2716037569df8261f565453a

TBR=sdefresne@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=585700
Review-Url: https://codereview.chromium.org/2630763002
Cr-Commit-Position: refs/heads/master@{#443622}
Committed: https://chromium.googlesource.com/chromium/src/+/de0a5c0273ea322431f88c0c3dbc333666ae1c30

[Eugene But (OOO till 7-30), 2017-01-13 18:36:41]

The CQ bit was checked by eugenebut@chromium.org

[Eugene But (OOO till 7-30), 2017-01-13 18:36:42]

Created Revert of Remove support for GlobalNetworkClientFactory from
RequestTracker.

[commit-bot: I haz the power, 2017-01-13 18:37:18]

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, 2017-01-13 18:38:04]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1484332601884420, "parent_rev":
"f7be987d1b081aa826af6d842e27608dd47a7cff", "commit_rev":
"de0a5c0273ea322431f88c0c3dbc333666ae1c30"}

[commit-bot: I haz the power, 2017-01-13 18:38:37]

Description was changed from

==========
Revert of Remove support for GlobalNetworkClientFactory from RequestTracker.
(patchset #1 id:1 of https://codereview.chromium.org/2633453004/ )

Reason for revert:
Base CL breaks CroNet: https://codereview.chromium.org/2627973005

Original issue's description:
> Remove support for GlobalNetworkClientFactory from RequestTracker.
> 
> The method RequestTracker::AddGlobalNetworkClientFactory is never
> called so remove the method and the support code.
> 
> BUG=585700
> 
> Review-Url: https://codereview.chromium.org/2633453004
> Cr-Commit-Position: refs/heads/master@{#443591}
> Committed:
https://chromium.googlesource.com/chromium/src/+/12bd970214af9f7a2716037569df...

TBR=sdefresne@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=585700
==========

to

==========
Revert of Remove support for GlobalNetworkClientFactory from RequestTracker.
(patchset #1 id:1 of https://codereview.chromium.org/2633453004/ )

Reason for revert:
Base CL breaks CroNet: https://codereview.chromium.org/2627973005

Original issue's description:
> Remove support for GlobalNetworkClientFactory from RequestTracker.
> 
> The method RequestTracker::AddGlobalNetworkClientFactory is never
> called so remove the method and the support code.
> 
> BUG=585700
> 
> Review-Url: https://codereview.chromium.org/2633453004
> Cr-Commit-Position: refs/heads/master@{#443591}
> Committed:
https://chromium.googlesource.com/chromium/src/+/12bd970214af9f7a2716037569df...

TBR=sdefresne@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=585700

Review-Url: https://codereview.chromium.org/2630763002
Cr-Commit-Position: refs/heads/master@{#443622}
Committed:
https://chromium.googlesource.com/chromium/src/+/de0a5c0273ea322431f88c0c3dbc...
==========

[commit-bot: I haz the power, 2017-01-13 18:38:39]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/de0a5c0273ea322431f88c0c3dbc...