Remove MessageLoop::current()->task_runner() in ui.

Remove MessageLoop::current()->task_runner() in ui.

This CL replaces MessageLoop::current()->task_runner() with
ThreadTaskRunnerHandle::Get() in ui.

In files where this replacement is made, it adds these include:
  #include "base/threading/thread_task_runner_handle.h"
  #include "base/location.h" (if required)
  #include "base/single_thread_task_runner.h" (if required)
And removes this include if it is no longer required:
  #include "base/message_loop/message_loop.h"

Why?
The fact that there's a MessageLoop on the thread is an
unnecessary implementation detail. When browser threads
are migrated to base/task_scheduler, tasks will no longer
have access to a MessageLoop but they will have access to
a ThreadTaskRunnerHandle.

Steps to generate this patch:
1. Run message_loop_cleanup_2.py (see code on the bug).
2. Run tools/sort-headers.py on modified files.
3. Run git cl format.

BUG=616447
R=thakis@chromium.org

Committed: https://crrev.com/13b955d465a1e4ce91961710091c7707f38a9d98
Cr-Commit-Position: refs/heads/master@{#399739}

[fdoray, 2016-06-09 13:21:49]

Can you review this CL? Thanks.

[fdoray, 2016-06-13 21:04:33]

fdoray@chromium.org changed reviewers:
+ sky@chromium.org

[fdoray, 2016-06-13 21:04:39]

+sky@: Can you review this CL? (Nico traveling)

[Nico, 2016-06-14 13:15:05]

lgtm

[fdoray, 2016-06-14 16:56:29]

The CQ bit was checked by fdoray@chromium.org

[fdoray, 2016-06-14 16:56:30]

The patchset sent to the CQ was uploaded after l-g-t-m from thakis@chromium.org
Link to the patchset: https://codereview.chromium.org/2054573002/#ps20001
(title: "rebase")

[commit-bot: I haz the power, 2016-06-14 16:56:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2054573002/20001

[commit-bot: I haz the power, 2016-06-14 17:47:25]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-06-14 17:47:38]

CQ bit was unchecked

[commit-bot: I haz the power, 2016-06-14 17:50:03]

Description was changed from

==========
Remove MessageLoop::current()->task_runner() in ui.

This CL replaces MessageLoop::current()->task_runner() with
ThreadTaskRunnerHandle::Get() in ui.

In files where this replacement is made, it adds these include:
  #include "base/threading/thread_task_runner_handle.h"
  #include "base/location.h" (if required)
  #include "base/single_thread_task_runner.h" (if required)
And removes this include if it is no longer required:
  #include "base/message_loop/message_loop.h"

Why?
The fact that there's a MessageLoop on the thread is an
unnecessary implementation detail. When browser threads
are migrated to base/task_scheduler, tasks will no longer
have access to a MessageLoop but they will have access to
a ThreadTaskRunnerHandle.

Steps to generate this patch:
1. Run message_loop_cleanup_2.py (see code on the bug).
2. Run tools/sort-headers.py on modified files.
3. Run git cl format.

BUG=616447
R=thakis@chromium.org
==========

to

==========
Remove MessageLoop::current()->task_runner() in ui.

This CL replaces MessageLoop::current()->task_runner() with
ThreadTaskRunnerHandle::Get() in ui.

In files where this replacement is made, it adds these include:
  #include "base/threading/thread_task_runner_handle.h"
  #include "base/location.h" (if required)
  #include "base/single_thread_task_runner.h" (if required)
And removes this include if it is no longer required:
  #include "base/message_loop/message_loop.h"

Why?
The fact that there's a MessageLoop on the thread is an
unnecessary implementation detail. When browser threads
are migrated to base/task_scheduler, tasks will no longer
have access to a MessageLoop but they will have access to
a ThreadTaskRunnerHandle.

Steps to generate this patch:
1. Run message_loop_cleanup_2.py (see code on the bug).
2. Run tools/sort-headers.py on modified files.
3. Run git cl format.

BUG=616447
R=thakis@chromium.org

Committed: https://crrev.com/13b955d465a1e4ce91961710091c7707f38a9d98
Cr-Commit-Position: refs/heads/master@{#399739}
==========

[commit-bot: I haz the power, 2016-06-14 17:50:04]

Patchset 2 (id:??) landed as
https://crrev.com/13b955d465a1e4ce91961710091c7707f38a9d98
Cr-Commit-Position: refs/heads/master@{#399739}