WifiDataProviderChromeOs: Call NetworkHandler from correct task runner.

WifiDataProviderChromeOs: Call NetworkHandler from correct task runner.

At some point, WifiDataProviderChromeOs construction changed to the
GeolocationProviderImpl thread, making the following code in its
constructor incorrect:

main_task_runner_(base::ThreadTaskRunnerHandle::Get())

Rather than relying on a "main" task runner for NetworkHandger calls,
use NetworkHandler::Get()->task_runner() instead.

BUG=674153, 661304
Review-Url: https://codereview.chromium.org/2584733002
Cr-Commit-Position: refs/heads/master@{#439253}
(cherry picked from commit 43c6a582d94fe6ec49330636c819601650f63a24)

Review-Url: https://codereview.chromium.org/2645133002 .
Cr-Commit-Position: refs/branch-heads/2924@{#818}
Cr-Branched-From: 3a87aecc31cd1ffe751dd72c04e5a96a1fc8108a-refs/heads/master@{#433059}
Committed: https://chromium.googlesource.com/chromium/src/+/4c7e0db8fdd332bda882e134f8f58b73a7a6f0aa

[stevenjb, 2017-01-20 17:30:23]

Description was changed from

==========
WifiDataProviderChromeOs: Call NetworkHandler from correct task runner.

At some point, WifiDataProviderChromeOs construction changed to the
GeolocationProviderImpl thread, making the following code in its
constructor incorrect:

main_task_runner_(base::ThreadTaskRunnerHandle::Get())

Rather than relying on a "main" task runner for NetworkHandger calls,
use NetworkHandler::Get()->task_runner() instead.

BUG=674153, 661304

Review-Url: https://codereview.chromium.org/2584733002
Cr-Commit-Position: refs/heads/master@{#439253}
(cherry picked from commit 43c6a582d94fe6ec49330636c819601650f63a24)
==========

to

==========
WifiDataProviderChromeOs: Call NetworkHandler from correct task runner.

At some point, WifiDataProviderChromeOs construction changed to the
GeolocationProviderImpl thread, making the following code in its
constructor incorrect:

main_task_runner_(base::ThreadTaskRunnerHandle::Get())

Rather than relying on a "main" task runner for NetworkHandger calls,
use NetworkHandler::Get()->task_runner() instead.

BUG=674153, 661304

Review-Url: https://codereview.chromium.org/2584733002
Cr-Commit-Position: refs/heads/master@{#439253}
(cherry picked from commit 43c6a582d94fe6ec49330636c819601650f63a24)

Review-Url: https://codereview.chromium.org/2645133002 .
Cr-Commit-Position: refs/branch-heads/2924@{#818}
Cr-Branched-From:
3a87aecc31cd1ffe751dd72c04e5a96a1fc8108a-refs/heads/master@{#433059}
Committed:
https://chromium.googlesource.com/chromium/src/+/4c7e0db8fdd332bda882e134f8f5...
==========

[stevenjb, 2017-01-20 17:30:25]

Committed patchset #1 (id:1) manually as
4c7e0db8fdd332bda882e134f8f58b73a7a6f0aa.