Fix leaks in InputConnectionHandlerThread

Fix leaks in InputConnectionHandlerThread

On destruction of ContentViewCore and on view detachment, we reset mHandler,
allowing it a chance to be garbage-collected.

BUG=668692
(directly cherry-picked from patchset http://crrev.com/2537073002#ps20001
 for early QA pass purposes, as requested by TPM)

Committed: https://chromium.googlesource.com/chromium/src/+/c7860ebf0f5005dfe519f5abc0a352ce680144f5

[Changwan Ryu, 2016-11-30 02:00:22]

Description was changed from

==========
Fix leaks in InputConnectionHandlerThread

On destruction of ContentViewCore and on view detachment, we reset mHandler,
allowing it a chance to be garbage-collected.

BUG=668692

(directly cherry-picked from patchset http://crrev.com/2537073002#ps20001
 for early QA pass purposes, as requested by TPM)
==========

to

==========
Fix leaks in InputConnectionHandlerThread

On destruction of ContentViewCore and on view detachment, we reset mHandler,
allowing it a chance to be garbage-collected.

BUG=668692

(directly cherry-picked from patchset http://crrev.com/2537073002#ps20001
 for early QA pass purposes, as requested by TPM)

Committed:
https://chromium.googlesource.com/chromium/src/+/c7860ebf0f5005dfe519f5abc0a3...
==========

[Changwan Ryu, 2016-11-30 02:00:24]

Committed patchset #1 (id:1) manually as
c7860ebf0f5005dfe519f5abc0a352ce680144f5.