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

Source/core/html/HTMLPlugInElement.cpp

Index: Source/core/html/HTMLPlugInElement.cpp
diff --git a/Source/core/html/HTMLPlugInElement.cpp b/Source/core/html/HTMLPlugInElement.cpp
index a1a36515039e106a6dc8d6620d648889858107f3..cde74055127060bfdae14c9d5a8a6a459bdfa1dc 100644
--- a/Source/core/html/HTMLPlugInElement.cpp
+++ b/Source/core/html/HTMLPlugInElement.cpp
@@ -116,6 +116,8 @@ void HTMLPlugInElement::setPersistedPluginWidget(Widget* widget)
         LocalFrame* frame = toPluginView(m_persistedPluginWidget.get())->pluginFrame();
         ASSERT(frame);
         frame->unregisterPluginElement(this);
+        if (!widget)
+            m_persistedPluginWidget->dispose();

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

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

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

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.

     }
     if (widget && widget->isPluginView()) {
         LocalFrame* frame = toPluginView(widget)->pluginFrame();