Use a MIG call when creating a plug-in property list file

Use a MIG call when creating a plug-in property list file
https://bugs.webkit.org/show_bug.cgi?id=84084
<rdar://problem/11197341>

Reviewed by Sam Weinig.

* Plugins/Hosted/NetscapePluginHostManager.mm:
(WebKit::NetscapePluginHostManager::createPropertyListFile):
Get a plug-in host and call _WKPHCreatePluginMIMETypesPreferences instead.

* Plugins/Hosted/WebKitPluginHost.defs:
Add PHCreatePluginMIMETypesPreferences.

* Plugins/WebNetscapePluginPackage.mm:
(-[WebNetscapePluginPackage createPropertyListFile]):
NetscapePluginHostManager::createPropertyListFile is no longer a static member function.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@114307 268f45cc-cd09-0410-ab3c-d52691b4dbfc