Remove null checking in JavaObjectWeakGlobalRef ctr

Remove null checking in JavaObjectWeakGlobalRef ctr

It is legal to create a weak reference to null. Removes the defensive
null checking being done in the constructors.

BUG=649407
Committed: https://crrev.com/48678a7b6e9087357262f8acee9df186b337d706
Cr-Commit-Position: refs/heads/master@{#423143}

[Jinsuk Kim, 2016-10-05 01:05:55]

jinsukkim@chromium.org changed reviewers:
+ torne@chromium.org

[Torne, 2016-10-05 10:41:26]

lgtm

[Jinsuk Kim, 2016-10-05 12:58:56]

The CQ bit was checked by jinsukkim@chromium.org

[commit-bot: I haz the power, 2016-10-05 12:59:11]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-05 13:41:37]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-05 13:43:42]

Description was changed from

==========
Remove null checking in JavaObjectWeakGlobalRef ctr

It is legal to create a weak reference to null. Removes the defensive
null checking being done in the constructors.

BUG=649407
==========

to

==========
Remove null checking in JavaObjectWeakGlobalRef ctr

It is legal to create a weak reference to null. Removes the defensive
null checking being done in the constructors.

BUG=649407

Committed: https://crrev.com/48678a7b6e9087357262f8acee9df186b337d706
Cr-Commit-Position: refs/heads/master@{#423143}
==========

[commit-bot: I haz the power, 2016-10-05 13:43:43]

Patchset 1 (id:??) landed as
https://crrev.com/48678a7b6e9087357262f8acee9df186b337d706
Cr-Commit-Position: refs/heads/master@{#423143}