Check pointers convertible not values in sk_sp.

Check pointers convertible not values in sk_sp.

The intent is to participate in overload resolution when the
pointers are convertible, which is a bit different from when the
values are convertible. This change makes sk_sp more consistent with
unique_ptr.

[bungeman-skia, 2016-03-05 13:21:29]

Description was changed from

==========
Check pointers convertible not values in sk_sp.

The intent is to participate in overload resolution when the
pointers are convertible, which is a bit different from when the
values are convertible. This change makes us more consitent with
unique_ptr.
==========

to

==========
Check pointers convertible not values in sk_sp.

The intent is to participate in overload resolution when the
pointers are convertible, which is a bit different from when the
values are convertible. This change makes us more consitent with
unique_ptr.
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

[bungeman-skia, 2016-03-05 13:22:30]

The CQ bit was checked by bungeman@google.com to run a CQ dry run

[commit-bot: I haz the power, 2016-03-05 13:22:32]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1762273004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1762273004/1

[bungeman-skia, 2016-03-05 13:22:53]

Description was changed from

==========
Check pointers convertible not values in sk_sp.

The intent is to participate in overload resolution when the
pointers are convertible, which is a bit different from when the
values are convertible. This change makes us more consitent with
unique_ptr.
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

to

==========
Check pointers convertible not values in sk_sp.

The intent is to participate in overload resolution when the
pointers are convertible, which is a bit different from when the
values are convertible. This change makes sk_sp more consistent with
unique_ptr.
==========

[commit-bot: I haz the power, 2016-03-05 13:32:06]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-03-05 13:32:07]

Dry run: This issue passed the CQ dry run.

[bungeman-skia, 2016-03-05 16:24:06]

bungeman@google.com changed reviewers:
+ halcanary@google.com, mtklein@google.com, reed@google.com

[bungeman-skia, 2016-03-05 16:30:09]

closed in favor of https://codereview.chromium.org/1771583002/ which has a test