Revert of aw: Ensure WebView stays alive until functor detach

Revert of aw: Ensure WebView stays alive until functor detach (patchset #1 id:1 of https://codereview.chromium.org/1880243004/ )

Reason for revert:
API changed

Original issue's description:
> aw: Ensure WebView stays alive until functor detach
>
> Android will not guarantee that the WebView is not garbage colllected
> before functor detached is called. So we need to add a gc root while the
> functor detached callback is pending.
>
> BUG=597167
>
> Committed: https://crrev.com/8e2e091e5c565b90e76ceb85dd4c848013c5cf94
> Cr-Commit-Position: refs/heads/master@{#387071}

TBR=tobiasjs@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=597167
Committed: https://crrev.com/3400c0da62249a66b9e6f5f0f6ef27dd89c50926
Cr-Commit-Position: refs/heads/master@{#387773}

[boliu, 2016-04-15 23:56:05]

Created Revert of aw: Ensure WebView stays alive until functor detach

[commit-bot: I haz the power, 2016-04-15 23:57:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1897583002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1897583002/1

[commit-bot: I haz the power, 2016-04-16 00:02:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1897583002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1897583002/1

[commit-bot: I haz the power, 2016-04-16 00:32:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1897583002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1897583002/1

[commit-bot: I haz the power, 2016-04-16 00:58:33]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-16 00:59:56]

Description was changed from

==========
Revert of aw: Ensure WebView stays alive until functor detach (patchset #1 id:1
of https://codereview.chromium.org/1880243004/ )

Reason for revert:
API changed

Original issue's description:
> aw: Ensure WebView stays alive until functor detach
> 
> Android will not guarantee that the WebView is not garbage colllected
> before functor detached is called. So we need to add a gc root while the
> functor detached callback is pending.
> 
> BUG=597167
> 
> Committed: https://crrev.com/8e2e091e5c565b90e76ceb85dd4c848013c5cf94
> Cr-Commit-Position: refs/heads/master@{#387071}

TBR=tobiasjs@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=597167
==========

to

==========
Revert of aw: Ensure WebView stays alive until functor detach (patchset #1 id:1
of https://codereview.chromium.org/1880243004/ )

Reason for revert:
API changed

Original issue's description:
> aw: Ensure WebView stays alive until functor detach
>
> Android will not guarantee that the WebView is not garbage colllected
> before functor detached is called. So we need to add a gc root while the
> functor detached callback is pending.
>
> BUG=597167
>
> Committed: https://crrev.com/8e2e091e5c565b90e76ceb85dd4c848013c5cf94
> Cr-Commit-Position: refs/heads/master@{#387071}

TBR=tobiasjs@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=597167

Committed: https://crrev.com/3400c0da62249a66b9e6f5f0f6ef27dd89c50926
Cr-Commit-Position: refs/heads/master@{#387773}
==========

[commit-bot: I haz the power, 2016-04-16 00:59:56]

Patchset 1 (id:??) landed as
https://crrev.com/3400c0da62249a66b9e6f5f0f6ef27dd89c50926
Cr-Commit-Position: refs/heads/master@{#387773}