Oilpan: update plugin handling to work over plugins persisted over reattach

Oilpan: update plugin handling to work over plugins persisted over reattach

Following Blink r201401, a plugin element's persisted plugin will be
cleared out upon the plugin element being removed from the tree or being
re-attached and there being no layout object. With Oilpan, this may
bring about disposal of the underlying plugin.

A disposed persisted plugin is consequently observable if subsequently
try to return the plugin wrapper object for the plugin element -- add
the required check so as to handle this properly.

R=haraken
BUG=526999
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=201572

[sof, 2015-09-01 13:44:42]

sigbjornf@opera.com changed reviewers:
+ oilpan-reviews@chromium.org

[sof, 2015-09-01 13:44:43]

please take a look.

[haraken, 2015-09-01 14:32:24]

haraken@chromium.org changed reviewers:
+ haraken@chromium.org

[haraken, 2015-09-01 14:32:25]

LGTM

https://codereview.chromium.org/1326603002/diff/1/Source/core/html/HTMLPlugIn...
File Source/core/html/HTMLPlugInElement.cpp (right):

https://codereview.chromium.org/1326603002/diff/1/Source/core/html/HTMLPlugIn...
Source/core/html/HTMLPlugInElement.cpp:120: m_persistedPluginWidget->dispose();

I'm wondering why we don't call m_persistedPluginWidget->dispose() in non-oilpan
as well.

[sof, 2015-09-01 21:37:31]

https://codereview.chromium.org/1326603002/diff/1/Source/core/html/HTMLPlugIn...
File Source/core/html/HTMLPlugInElement.cpp (right):

https://codereview.chromium.org/1326603002/diff/1/Source/core/html/HTMLPlugIn...
Source/core/html/HTMLPlugInElement.cpp:120: m_persistedPluginWidget->dispose();
On 2015/09/01 14:32:25, haraken wrote:
> 
> I'm wondering why we don't call m_persistedPluginWidget->dispose() in
non-oilpan
> as well.

The prompt disposal (via deref() on clearing) will implicitly call dispose(),
non-Oilpan. That's where/how we left it when moving Widget / plugin containers
over to the Oilpan heap.

[sof, 2015-09-01 21:37:37]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2015-09-01 21:38:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1326603002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1326603002/1

[commit-bot: I haz the power, 2015-09-01 21:46:24]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=201572