Clear UIThreadExtensionFunction::render_frame_host_ when RFH is gone.

Clear UIThreadExtensionFunction::render_frame_host_ when RFH is gone.

This regressed in my CL r395494 where I mistakenly put a short circuit
in SetRenderFrameHost. SetRenderFrameHost is called with nullptr RFH
when WebContentsObserver::RenderFrameDeleted() happens (for
non service worker case).

BUG=616119
Test=See clusterfuzz repro, it infrequently reproduces though. But
I was able to verify with this CL that the crash shouldn't happen.

Committed: https://crrev.com/fd6715d5469aaa2fa05bc3ab316767d6ea84867e
Cr-Commit-Position: refs/heads/master@{#397432}

[lazyboy, 2016-06-01 23:40:08]

Description was changed from

==========
Clear UIThreadExtensionFunction::render_frame_host_ when RFH is gone.

This regressed in my CL r395494 where I mistakenly put a short circuit
in SetRenderFrameHost. SetRenderFrameHost is called with nullptr RFH
when WebContentsObserver::RenderFrameDeleted() happens.

BUG=616119
Test=See clusterfuzz repro, it infrequently reproduces though. But
I was able to verify with this CL that the crash shouldn't happen.
==========

to

==========
Clear UIThreadExtensionFunction::render_frame_host_ when RFH is gone.

This regressed in my CL r395494 where I mistakenly put a short circuit
in SetRenderFrameHost. SetRenderFrameHost is called with nullptr RFH
when WebContentsObserver::RenderFrameDeleted() happens (for
non service worker case).

BUG=616119
Test=See clusterfuzz repro, it infrequently reproduces though. But
I was able to verify with this CL that the crash shouldn't happen.
==========

[lazyboy, 2016-06-01 23:40:24]

lazyboy@chromium.org changed reviewers:
+ rdevlin.cronin@chromium.org

[Devlin, 2016-06-02 00:16:14]

lgtm

[lazyboy, 2016-06-02 00:59:21]

The CQ bit was checked by lazyboy@chromium.org

[commit-bot: I haz the power, 2016-06-02 01:00:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2034543002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2034543002/1

[commit-bot: I haz the power, 2016-06-02 02:10:48]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-06-02 02:10:48]

Try jobs failed on following builders:
  linux_chromium_chromeos_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[lazyboy, 2016-06-02 15:05:51]

The CQ bit was checked by lazyboy@chromium.org

[commit-bot: I haz the power, 2016-06-02 15:06:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2034543002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2034543002/1

[commit-bot: I haz the power, 2016-06-02 16:08:41]

Description was changed from

==========
Clear UIThreadExtensionFunction::render_frame_host_ when RFH is gone.

This regressed in my CL r395494 where I mistakenly put a short circuit
in SetRenderFrameHost. SetRenderFrameHost is called with nullptr RFH
when WebContentsObserver::RenderFrameDeleted() happens (for
non service worker case).

BUG=616119
Test=See clusterfuzz repro, it infrequently reproduces though. But
I was able to verify with this CL that the crash shouldn't happen.
==========

to

==========
Clear UIThreadExtensionFunction::render_frame_host_ when RFH is gone.

This regressed in my CL r395494 where I mistakenly put a short circuit
in SetRenderFrameHost. SetRenderFrameHost is called with nullptr RFH
when WebContentsObserver::RenderFrameDeleted() happens (for
non service worker case).

BUG=616119
Test=See clusterfuzz repro, it infrequently reproduces though. But
I was able to verify with this CL that the crash shouldn't happen.
==========

[commit-bot: I haz the power, 2016-06-02 16:08:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-02 16:10:39]

Description was changed from

==========
Clear UIThreadExtensionFunction::render_frame_host_ when RFH is gone.

This regressed in my CL r395494 where I mistakenly put a short circuit
in SetRenderFrameHost. SetRenderFrameHost is called with nullptr RFH
when WebContentsObserver::RenderFrameDeleted() happens (for
non service worker case).

BUG=616119
Test=See clusterfuzz repro, it infrequently reproduces though. But
I was able to verify with this CL that the crash shouldn't happen.
==========

to

==========
Clear UIThreadExtensionFunction::render_frame_host_ when RFH is gone.

This regressed in my CL r395494 where I mistakenly put a short circuit
in SetRenderFrameHost. SetRenderFrameHost is called with nullptr RFH
when WebContentsObserver::RenderFrameDeleted() happens (for
non service worker case).

BUG=616119
Test=See clusterfuzz repro, it infrequently reproduces though. But
I was able to verify with this CL that the crash shouldn't happen.

Committed: https://crrev.com/fd6715d5469aaa2fa05bc3ab316767d6ea84867e
Cr-Commit-Position: refs/heads/master@{#397432}
==========

[commit-bot: I haz the power, 2016-06-02 16:10:40]

Patchset 1 (id:??) landed as
https://crrev.com/fd6715d5469aaa2fa05bc3ab316767d6ea84867e
Cr-Commit-Position: refs/heads/master@{#397432}