remember the last metafile, instead of the last canvas

remember the last metafile, instead of the last canvas

SkCanvas is marked to become NOT reference counted (its very problematic today, since a canvas can (and often is) be on the stack).

The current code in plugins rely on "ref"ing the last canvas it saw, so that later it can extract the "metafile" from it and use that (in printEnd). This itself is a bit odd, since there is no explicit mapping between the lifetime of the canvas and the lifetime of the metafile.

This change just makes bare what is going on: we remember the last metafile we've seen (by extracting it from the canvas each time we see a canvas), and then use it directly in printEnd.

This does require that the metafile be valid until printEnd is called, but that was a necessary promise all along.

BUG=

Committed: https://crrev.com/b8367dc404046305d17bb691075531da1da2c0c5
Cr-Commit-Position: refs/heads/master@{#433542}

[reed1, 2016-11-18 19:00:22]

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

[commit-bot: I haz the power, 2016-11-18 19:01:18]

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

[reed1, 2016-11-18 20:23:45]

reed@google.com changed reviewers:
+ bbudge@chromium.org, raymes@chromium.org, thestig@chromium.org

[reed1, 2016-11-18 20:27:03]

Description was changed from

==========
remember the last metafile, instead of the last canvas

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

to

==========
remember the last metafile, instead of the last canvas

SkCanvas is marked to become NOT reference counted (its very problematic today,
since a canvas can (and often is) be on the stack).

The current code in plugins rely on "ref"ing the last canvas it saw, so that
later it can extract the "metafile" from it and use that (in printEnd). This
itself is a bit odd, since there is no explicit mapping between the lifetime of
the canvas and the lifetime of the metafile.

This change just makes bare what is going on: we remember the last metafile
we've seen (by extracting it from the canvas each time we see a canvas), and
then use it directly in printEnd.

This does require that the metafile be valid until printEnd is called, but that
was a necessary promise all along.


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

[commit-bot: I haz the power, 2016-11-18 20:56:24]

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

[commit-bot: I haz the power, 2016-11-18 20:56:25]

Dry run: This issue passed the CQ dry run.

[bbudge, 2016-11-18 21:18:51]

lgtm

[Lei Zhang, 2016-11-18 22:14:51]

Printing works for me with this CL, so lgtm.

[reed1, 2016-11-18 22:15:37]

The CQ bit was checked by reed@google.com

[commit-bot: I haz the power, 2016-11-18 22:16:22]

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

[reed1, 2016-11-18 22:29:53]

The CQ bit was unchecked by reed@google.com

[reed1, 2016-11-21 14:02:51]

The CQ bit was checked by reed@google.com

[commit-bot: I haz the power, 2016-11-21 14:03:09]

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, 2016-11-21 14:45:44]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1479736971716020, "parent_rev":
["37ba512a59c52e7fcb8ced17a5672315efaa0822", null], "commit_rev":
["1d68aadb7ece9431361ba2bb9ba759ec3863fadd", null]}

[commit-bot: I haz the power, 2016-11-21 14:46:07]

Description was changed from

==========
remember the last metafile, instead of the last canvas

SkCanvas is marked to become NOT reference counted (its very problematic today,
since a canvas can (and often is) be on the stack).

The current code in plugins rely on "ref"ing the last canvas it saw, so that
later it can extract the "metafile" from it and use that (in printEnd). This
itself is a bit odd, since there is no explicit mapping between the lifetime of
the canvas and the lifetime of the metafile.

This change just makes bare what is going on: we remember the last metafile
we've seen (by extracting it from the canvas each time we see a canvas), and
then use it directly in printEnd.

This does require that the metafile be valid until printEnd is called, but that
was a necessary promise all along.


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

to

==========
remember the last metafile, instead of the last canvas

SkCanvas is marked to become NOT reference counted (its very problematic today,
since a canvas can (and often is) be on the stack).

The current code in plugins rely on "ref"ing the last canvas it saw, so that
later it can extract the "metafile" from it and use that (in printEnd). This
itself is a bit odd, since there is no explicit mapping between the lifetime of
the canvas and the lifetime of the metafile.

This change just makes bare what is going on: we remember the last metafile
we've seen (by extracting it from the canvas each time we see a canvas), and
then use it directly in printEnd.

This does require that the metafile be valid until printEnd is called, but that
was a necessary promise all along.


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

[commit-bot: I haz the power, 2016-11-21 14:46:08]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-21 14:47:51]

Description was changed from

==========
remember the last metafile, instead of the last canvas

SkCanvas is marked to become NOT reference counted (its very problematic today,
since a canvas can (and often is) be on the stack).

The current code in plugins rely on "ref"ing the last canvas it saw, so that
later it can extract the "metafile" from it and use that (in printEnd). This
itself is a bit odd, since there is no explicit mapping between the lifetime of
the canvas and the lifetime of the metafile.

This change just makes bare what is going on: we remember the last metafile
we've seen (by extracting it from the canvas each time we see a canvas), and
then use it directly in printEnd.

This does require that the metafile be valid until printEnd is called, but that
was a necessary promise all along.


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

to

==========
remember the last metafile, instead of the last canvas

SkCanvas is marked to become NOT reference counted (its very problematic today,
since a canvas can (and often is) be on the stack).

The current code in plugins rely on "ref"ing the last canvas it saw, so that
later it can extract the "metafile" from it and use that (in printEnd). This
itself is a bit odd, since there is no explicit mapping between the lifetime of
the canvas and the lifetime of the metafile.

This change just makes bare what is going on: we remember the last metafile
we've seen (by extracting it from the canvas each time we see a canvas), and
then use it directly in printEnd.

This does require that the metafile be valid until printEnd is called, but that
was a necessary promise all along.

BUG=

Committed: https://crrev.com/b8367dc404046305d17bb691075531da1da2c0c5
Cr-Commit-Position: refs/heads/master@{#433542}
==========

[commit-bot: I haz the power, 2016-11-21 14:47:52]

Patchset 1 (id:??) landed as
https://crrev.com/b8367dc404046305d17bb691075531da1da2c0c5
Cr-Commit-Position: refs/heads/master@{#433542}