Fix RemoteFrame detachment to signal its client.

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

[kenrb, 2014-11-07 18:43:05]

kenrb@chromium.org changed reviewers:
+ japhet@chromium.org

[kenrb, 2014-11-07 18:43:18]

Nate: PTAL?

[dcheng, 2014-11-07 18:46:37]

dcheng@chromium.org changed reviewers:
+ dcheng@chromium.org

[dcheng, 2014-11-07 18:46:38]

lgtm

[Nate Chapin, 2014-11-07 19:40:13]

lgtm

[kenrb, 2014-11-07 19:40:48]

The CQ bit was checked by kenrb@chromium.org

[commit-bot: I haz the power, 2014-11-07 19:41:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/712653002/1

[commit-bot: I haz the power, 2014-11-07 19:49:57]

Committed patchset #1 (id:1) as 184987

[raymes, 2014-11-10 01:16:07]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/699053004/ by raymes@chromium.org.

The reason for reverting is: Speculative revert to attempt to fix
https://code.google.com/p/chromium/issues/detail?id=431608.