Fix It2Me Host doesn't kill the native process after canceling a share

Fix It2Me Host doesn't kill the native process after canceling a share

Currently in the webapp, we didin't disconnect the native messaging port
after a share and therefore keeping the remote-assistance process alive.

Summary of changes:
1. Disconnect the native message port when the host status changes to
   DISCONNECTED or ERROR.
2. Remove remoting.hostSession global and wrap host_screen.js in an
   anonymous function.

BUG=416676
Committed: https://crrev.com/37e5586ce5de431a42bbc1e0e8c65e19a4ba0654
Cr-Commit-Position: refs/heads/master@{#314670}

[kelvinp, 2015-02-04 01:33:56]

kelvinp@chromium.org changed reviewers:
+ jamiewalch@chromium.org, sergeyu@chromium.org

[kelvinp, 2015-02-04 01:38:10]

PTAL

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
File remoting/webapp/crd/js/host_screen.js (left):

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
remoting/webapp/crd/js/host_screen.js:105: * @private
This CL wraps the entire file in an IEFE, so that onHostChanged is truly private
and invisible in other files.  Thus no need the @private annotation.

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
File remoting/webapp/crd/js/host_session.js (right):

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
remoting/webapp/crd/js/host_session.js:30: })();
JsCompile cannot handle enums (remoting.HostSession.State) defined inside an
anonymous function, thus the abrupt ending of the function here.

[Sergey Ulanov, 2015-02-04 19:52:47]

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
File remoting/webapp/crd/js/host_screen.js (right):

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
remoting/webapp/crd/js/host_screen.js:18: var hostSession_ = null;
I think this can be removed completely. tryShareWithToken_() just need to pass
it to all callbacks.

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
File remoting/webapp/crd/js/host_session.js (right):

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
remoting/webapp/crd/js/host_session.js:30: })();
On 2015/02/04 01:38:10, kelvinp wrote:
> JsCompile cannot handle enums (remoting.HostSession.State) defined inside an
> anonymous function, thus the abrupt ending of the function here.

I didn't have any problems with it inside dns_blackhole_checker.js:
https://code.google.com/p/chromium/codesearch#chromium/src/remoting/webapp/cr...

[Jamie, 2015-02-04 21:02:39]

lgtm

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
File remoting/webapp/crd/js/host_session.js (right):

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
remoting/webapp/crd/js/host_session.js:30: })();
On 2015/02/04 19:52:46, Sergey Ulanov wrote:
> On 2015/02/04 01:38:10, kelvinp wrote:
> > JsCompile cannot handle enums (remoting.HostSession.State) defined inside an
> > anonymous function, thus the abrupt ending of the function here.
> 
> I didn't have any problems with it inside dns_blackhole_checker.js:
>
https://code.google.com/p/chromium/codesearch#chromium/src/remoting/webapp/cr...

Alternatively, you could get rid of the IIFE for this file, since it doesn't
declare anything at global scope.

[kelvinp, 2015-02-04 21:35:55]

New patchsets have been uploaded after l-g-t-m from jamiewalch@chromium.org

[kelvinp, 2015-02-04 21:36:15]

FYI

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
File remoting/webapp/crd/js/host_screen.js (right):

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
remoting/webapp/crd/js/host_screen.js:18: var hostSession_ = null;
On 2015/02/04 19:52:46, Sergey Ulanov wrote:
> I think this can be removed completely. tryShareWithToken_() just need to pass
> it to all callbacks.

I think ultimately, we would want to encapsulate the host sharing flow in an
object.  For this CL, I just want to get rid of the global to prevent further
dependency on this object.  I would probably clean up this file in a separate
CL.

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
File remoting/webapp/crd/js/host_session.js (right):

https://codereview.chromium.org/895723006/diff/1/remoting/webapp/crd/js/host_...
remoting/webapp/crd/js/host_session.js:30: })();
On 2015/02/04 21:02:39, Jamie wrote:
> On 2015/02/04 19:52:46, Sergey Ulanov wrote:
> > On 2015/02/04 01:38:10, kelvinp wrote:
> > > JsCompile cannot handle enums (remoting.HostSession.State) defined inside
an
> > > anonymous function, thus the abrupt ending of the function here.
> > 
> > I didn't have any problems with it inside dns_blackhole_checker.js:
> >
>
https://code.google.com/p/chromium/codesearch#chromium/src/remoting/webapp/cr...
> 
> Alternatively, you could get rid of the IIFE for this file, since it doesn't
> declare anything at global scope.

This is because BlackholeState is not referenced anywhere outside of that file. 
But remoting.HostSession.State is referenced in this file. Removing the IIFE for
now.

[kelvinp, 2015-02-04 21:40:42]

The CQ bit was checked by kelvinp@chromium.org

[commit-bot: I haz the power, 2015-02-04 21:42:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/895723006/20001

[commit-bot: I haz the power, 2015-02-04 23:00:02]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-04 23:01:00]

Patchset 2 (id:??) landed as
https://crrev.com/37e5586ce5de431a42bbc1e0e8c65e19a4ba0654
Cr-Commit-Position: refs/heads/master@{#314670}