Reland of Delete unused TaskRunner abstraction.

Reland of Delete unused TaskRunner abstraction. (patchset #1 id:1 of https://codereview.webrtc.org/2732363004/ )

Reason for revert:
Chrome includes now updated, see cl https://codereview.chromium.org/2737133002/

Original issue's description:
> Revert of Delete unused TaskRunner abstraction. (patchset #2 id:20001 of https://codereview.webrtc.org/2622923002/ )
> 
> Reason for revert:
> I had missed updating a few of Chrome's #includes, breaking the build.
> 
> Original issue's description:
> > Delete unused TaskRunner abstraction.
> > 
> > This is the fifth and final step in the process started in cl https://codereview.webrtc.org/2696703009/
> > 
> > Depends on the landing of a copy of this code in Chrome (step 4), cl 
> > https://codereview.chromium.org/2694903005/
> > 
> > BUG=webrtc:6424
> > 
> > Review-Url: https://codereview.webrtc.org/2622923002
> > Cr-Commit-Position: refs/heads/master@{#17107}
> > Committed: https://chromium.googlesource.com/external/webrtc/+/2d15fdd91bc8b63a5659a8d48b7460cb2308e7a2
> 
> TBR=pthatcher@webrtc.org,kjellander@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6424
> 
> Review-Url: https://codereview.webrtc.org/2732363004
> Cr-Commit-Position: refs/heads/master@{#17109}
> Committed: https://chromium.googlesource.com/external/webrtc/+/9900be313c212c276377d406585b706079f8bc41

TBR=pthatcher@webrtc.org,kjellander@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6424
Review-Url: https://codereview.webrtc.org/2740063002
Cr-Commit-Position: refs/heads/master@{#17131}
Committed: https://chromium.googlesource.com/external/webrtc/+/b05d9b292a17f7f480555454a4cf888b32288172

[nisse-webrtc, 2017-03-09 08:37:10]

The CQ bit was checked by nisse@webrtc.org

[nisse-webrtc, 2017-03-09 08:37:11]

Created Reland of Delete unused TaskRunner abstraction.

[commit-bot: I haz the power, 2017-03-09 08:37:20]

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

[commit-bot: I haz the power, 2017-03-09 08:37:26]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1489048630979560, "parent_rev":
"d6652076011363ab329d5cc4643619e4728303c7", "commit_rev":
"b05d9b292a17f7f480555454a4cf888b32288172"}

[commit-bot: I haz the power, 2017-03-09 08:37:29]

Description was changed from

==========
Reland of Delete unused TaskRunner abstraction. (patchset #1 id:1 of
https://codereview.webrtc.org/2732363004/ )

Reason for revert:
Chrome includes now updated, see cl https://codereview.chromium.org/2737133002/

Original issue's description:
> Revert of Delete unused TaskRunner abstraction. (patchset #2 id:20001 of
https://codereview.webrtc.org/2622923002/ )
> 
> Reason for revert:
> I had missed updating a few of Chrome's #includes, breaking the build.
> 
> Original issue's description:
> > Delete unused TaskRunner abstraction.
> > 
> > This is the fifth and final step in the process started in cl
https://codereview.webrtc.org/2696703009/
> > 
> > Depends on the landing of a copy of this code in Chrome (step 4), cl 
> > https://codereview.chromium.org/2694903005/
> > 
> > BUG=webrtc:6424
> > 
> > Review-Url: https://codereview.webrtc.org/2622923002
> > Cr-Commit-Position: refs/heads/master@{#17107}
> > Committed:
https://chromium.googlesource.com/external/webrtc/+/2d15fdd91bc8b63a5659a8d48...
> 
> TBR=pthatcher@webrtc.org,kjellander@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6424
> 
> Review-Url: https://codereview.webrtc.org/2732363004
> Cr-Commit-Position: refs/heads/master@{#17109}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/9900be313c212c276377d4065...

TBR=pthatcher@webrtc.org,kjellander@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6424
==========

to

==========
Reland of Delete unused TaskRunner abstraction. (patchset #1 id:1 of
https://codereview.webrtc.org/2732363004/ )

Reason for revert:
Chrome includes now updated, see cl https://codereview.chromium.org/2737133002/

Original issue's description:
> Revert of Delete unused TaskRunner abstraction. (patchset #2 id:20001 of
https://codereview.webrtc.org/2622923002/ )
> 
> Reason for revert:
> I had missed updating a few of Chrome's #includes, breaking the build.
> 
> Original issue's description:
> > Delete unused TaskRunner abstraction.
> > 
> > This is the fifth and final step in the process started in cl
https://codereview.webrtc.org/2696703009/
> > 
> > Depends on the landing of a copy of this code in Chrome (step 4), cl 
> > https://codereview.chromium.org/2694903005/
> > 
> > BUG=webrtc:6424
> > 
> > Review-Url: https://codereview.webrtc.org/2622923002
> > Cr-Commit-Position: refs/heads/master@{#17107}
> > Committed:
https://chromium.googlesource.com/external/webrtc/+/2d15fdd91bc8b63a5659a8d48...
> 
> TBR=pthatcher@webrtc.org,kjellander@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6424
> 
> Review-Url: https://codereview.webrtc.org/2732363004
> Cr-Commit-Position: refs/heads/master@{#17109}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/9900be313c212c276377d4065...

TBR=pthatcher@webrtc.org,kjellander@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6424

Review-Url: https://codereview.webrtc.org/2740063002
Cr-Commit-Position: refs/heads/master@{#17131}
Committed:
https://chromium.googlesource.com/external/webrtc/+/b05d9b292a17f7f480555454a...
==========

[commit-bot: I haz the power, 2017-03-09 08:37:29]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/webrtc/+/b05d9b292a17f7f480555454a...