Revert of Revert of Fix RemoteFrame detachment to signal its client.

Revert of Revert of Fix RemoteFrame detachment to signal its client. (patchset #1 id:1 of https://codereview.chromium.org/699053004/)

Reason for revert:
Reverting the revert. This turned out not to be the cause of https://code.google.com/p/chromium/issues/detail?id=431608

Original issue's description:
> Revert of Fix RemoteFrame detachment to signal its client. (patchset #1 id:1 of https://codereview.chromium.org/712653002/)
> 
> Reason for revert:
> Speculative revert to attempt to fix https://code.google.com/p/chromium/issues/detail?id=431608
> 
> Original issue's description:
> > Fix RemoteFrame detachment to signal its client.
> > 
> > We were seeing crashes in checkFrameCountConsistency() because during
> > RemoteFrame detachment the client was not getting signalled to modify
> > the frame tree, resulting in inconsistent state. This CL corrects that
> > problem.
> > 
> > BUG=430972
> > 
> > Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=184987
> 
> TBR=japhet@chromium.org,dcheng@chromium.org,kenrb@chromium.org
> NOTREECHECKS=true
> NOTRY=true
> BUG=430972
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=185015

TBR=japhet@chromium.org,dcheng@chromium.org,kenrb@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=430972
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=185018

[raymes, 2014-11-10 03:05:53]

Created Revert of Revert of Fix RemoteFrame detachment to signal its client.

[commit-bot: I haz the power, 2014-11-10 03:06:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/709363002/1

[commit-bot: I haz the power, 2014-11-10 03:06:54]

Committed patchset #1 (id:1) as 185018