Reland of Fix event page process cleanup when running in --isolate-extensions mode.

Reland of Fix event page process cleanup when running in --isolate-extensions mode. (patchset #1 id:1 of https://codereview.chromium.org/2044643003/ )

Reason for revert:
Reverting the revert, as the speculation of this CL being the root cause did not pan out - https://bugs.chromium.org/p/chromium/issues/detail?id=616989#c36.

Original issue's description:
> Revert of Fix event page process cleanup when running in --isolate-extensions mode. (patchset #6 id:100001 of https://codereview.chromium.org/2028873002/ )
>
> Reason for revert:
> Speculative revert of this CL to check if it is the root cause of https://crbug.com/616989.
>
> Original issue's description:
> > Fix event page process cleanup when running in --isolate-extensions mode.
> >
> > With --isolate-extensions, navigations can start in one RenderFrameHost
> > and complete in another. This was not possible to happen with extensions
> > related RenderFrameHosts in the past, so the code wasn't able to handle
> > it. This CL refactors the OnNetworkRequest(Started|Stopped) to use the
> > navigation request id as the stable identifier instead of the associated
> > RenderFrameHost.
> >
> > BUG=612668
> >
> > Committed: https://crrev.com/c25500369dd9a7f49d2b7d276556b2e22ba840c8
> > Cr-Commit-Position: refs/heads/master@{#397328}
>
> TBR=rdevlin.cronin@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=612668
>
> Committed: https://crrev.com/3cae185174cf799005ee4d4f6147e01fad45e354
> Cr-Commit-Position: refs/heads/master@{#398185}

TBR=rdevlin.cronin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=612668
Committed: https://crrev.com/d13fd29dbd8d0c7f09e527e704756eceada26fa0
Cr-Commit-Position: refs/heads/master@{#398367}

[nasko, 2016-06-07 20:10:22]

The CQ bit was checked by nasko@chromium.org

[nasko, 2016-06-07 20:10:23]

Created Reland of Fix event page process cleanup when running in
--isolate-extensions mode.

[commit-bot: I haz the power, 2016-06-07 20:32:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2040293002/1

[commit-bot: I haz the power, 2016-06-07 20:34:00]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-07 20:35:31]

Description was changed from

==========
Reland of Fix event page process cleanup when running in --isolate-extensions
mode. (patchset #1 id:1 of https://codereview.chromium.org/2044643003/ )

Reason for revert:
Reverting the revert, as the speculation of this CL being the root cause did not
pan out - https://bugs.chromium.org/p/chromium/issues/detail?id=616989#c36.

Original issue's description:
> Revert of Fix event page process cleanup when running in --isolate-extensions
mode. (patchset #6 id:100001 of https://codereview.chromium.org/2028873002/ )
> 
> Reason for revert:
> Speculative revert of this CL to check if it is the root cause of
https://crbug.com/616989.
> 
> Original issue's description:
> > Fix event page process cleanup when running in --isolate-extensions mode.
> >
> > With --isolate-extensions, navigations can start in one RenderFrameHost
> > and complete in another. This was not possible to happen with extensions
> > related RenderFrameHosts in the past, so the code wasn't able to handle
> > it. This CL refactors the OnNetworkRequest(Started|Stopped) to use the
> > navigation request id as the stable identifier instead of the associated
> > RenderFrameHost.
> >
> > BUG=612668
> >
> > Committed: https://crrev.com/c25500369dd9a7f49d2b7d276556b2e22ba840c8
> > Cr-Commit-Position: refs/heads/master@{#397328}
> 
> TBR=rdevlin.cronin@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=612668
> 
> Committed: https://crrev.com/3cae185174cf799005ee4d4f6147e01fad45e354
> Cr-Commit-Position: refs/heads/master@{#398185}

TBR=rdevlin.cronin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=612668
==========

to

==========
Reland of Fix event page process cleanup when running in --isolate-extensions
mode. (patchset #1 id:1 of https://codereview.chromium.org/2044643003/ )

Reason for revert:
Reverting the revert, as the speculation of this CL being the root cause did not
pan out - https://bugs.chromium.org/p/chromium/issues/detail?id=616989#c36.

Original issue's description:
> Revert of Fix event page process cleanup when running in --isolate-extensions
mode. (patchset #6 id:100001 of https://codereview.chromium.org/2028873002/ )
>
> Reason for revert:
> Speculative revert of this CL to check if it is the root cause of
https://crbug.com/616989.
>
> Original issue's description:
> > Fix event page process cleanup when running in --isolate-extensions mode.
> >
> > With --isolate-extensions, navigations can start in one RenderFrameHost
> > and complete in another. This was not possible to happen with extensions
> > related RenderFrameHosts in the past, so the code wasn't able to handle
> > it. This CL refactors the OnNetworkRequest(Started|Stopped) to use the
> > navigation request id as the stable identifier instead of the associated
> > RenderFrameHost.
> >
> > BUG=612668
> >
> > Committed: https://crrev.com/c25500369dd9a7f49d2b7d276556b2e22ba840c8
> > Cr-Commit-Position: refs/heads/master@{#397328}
>
> TBR=rdevlin.cronin@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=612668
>
> Committed: https://crrev.com/3cae185174cf799005ee4d4f6147e01fad45e354
> Cr-Commit-Position: refs/heads/master@{#398185}

TBR=rdevlin.cronin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=612668

Committed: https://crrev.com/d13fd29dbd8d0c7f09e527e704756eceada26fa0
Cr-Commit-Position: refs/heads/master@{#398367}
==========

[commit-bot: I haz the power, 2016-06-07 20:35:32]

Patchset 1 (id:??) landed as
https://crrev.com/d13fd29dbd8d0c7f09e527e704756eceada26fa0
Cr-Commit-Position: refs/heads/master@{#398367}