Reland Fix leak of RTCPeerConnectionHandler if PeerConnection.close() is called from js.…

This cl was originally reviewed in https://codereview.chromium.org/1438153002/. Patchset 1 is a pure re-upload.
Pachset 2 fix a bug in the original cl and adds a unit test.

Fix leak of RTCPeerConnectionHandler if PeerConnection.close() is called from js.
This fixes a bug where RTCPeerConnectionHandler::client_ is set to null when RTCPeerConnectionHandler.stop() is called.
RTCPeerConnectionHandler.stop() is a pretty bad name (override from blink::WebRTCPeerConnectionHandler) since it is triggered when JS or the browser process want to close a PeerConnection.
Since client_ was set to null, RTCPeerConnectionHandler::DestructAllHandlers did not delete RTCPeerConnectionHandler.

BUG=542132
Committed: https://crrev.com/93f225811f0767054c81f0368ac31b5a8448aeee
Cr-Commit-Position: refs/heads/master@{#359784}

[perkj_chrome, 2015-11-15 20:16:32]

Description was changed from

==========
Revert "Revert of Fix leak of RTCPeerConnectionHandler if PeerConnection.close()
is called from js. (patchset #3 id:40001 of
https://codereview.chromium.org/1438153002/ )"

This reverts commit 3b988e383919f9d99cc66c3c691342cbc2c1c063.

BUG=
==========

to

==========
This cl was originally reviewed in https://codereview.chromium.org/1438153002/.
Patchset 1 is a pure re-upload.
Pachset 2 fix a bug in the original cl and adds a unit test. 

Fix leak of RTCPeerConnectionHandler if PeerConnection.close() is called from
js.
This fixes a bug where RTCPeerConnectionHandler::client_ is set to null when
RTCPeerConnectionHandler.stop() is called.
RTCPeerConnectionHandler.stop() is a pretty bad name (override from
blink::WebRTCPeerConnectionHandler) since it is triggered when JS or the browser
process want to close a PeerConnection.
Since client_ was set to null, RTCPeerConnectionHandler::DestructAllHandlers did
not delete RTCPeerConnectionHandler.

BUG=542132
==========

[perkj_chrome, 2015-11-15 20:16:33]

perkj@chromium.org changed reviewers:
+ tommi@chromium.org

[perkj_chrome, 2015-11-15 20:19:12]

Please?

[tommi (sloooow) - chröme, 2015-11-15 20:27:28]

The CQ bit was checked by tommi@chromium.org

[tommi (sloooow) - chröme, 2015-11-15 20:27:29]

lgtm

[commit-bot: I haz the power, 2015-11-15 20:27:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1439973006/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1439973006/20001

[commit-bot: I haz the power, 2015-11-15 22:17:19]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-11-15 22:17:58]

Patchset 2 (id:??) landed as
https://crrev.com/93f225811f0767054c81f0368ac31b5a8448aeee
Cr-Commit-Position: refs/heads/master@{#359784}