Reviewed by Holger.

        https://bugs.webkit.org/show_bug.cgi?id=18882
        https://bugs.webkit.org/show_bug.cgi?id=18892
        Based also on work by Chris Lord.

        Provides support for NPAPI plugins that pass NULL as their instance
        info. There are two kinds:
        - Some call NPN_UserAgent and NPN_GetValue before a PluginView has
        been created. For those we provide static versions of those functions.
        - Others call NPN_* functions with a NULL instance inside NPP_*
        calls, for those we've added extra currentPluginView guards.

        * plugins/PluginView.cpp: Add additional currentPluginView guards and
        some small style changes.
        (WebCore::PluginView::start):
        (WebCore::PluginView::performRequest):
        (WebCore::PluginView::bindingInstance):
        (WebCore::PluginView::handlePost):
        * plugins/PluginView.h: Added static versions of NPN_UserAgent and
        NPN_GetValue.
        * plugins/gtk/PluginViewGtk.cpp: Add additional currentPluginView
        guards and some small style changes.
        (WebCore::PluginView::setNPWindowRect):
        (WebCore::PluginView::stop):
        (WebCore::PluginView::userAgentStatic): Added to deal with plugins
        that query this before having a PluginView.
        (WebCore::PluginView::getValueStatic): Added to deal with plugins
        that call this before we have created a PluginView.
        (WebCore::PluginView::getValue): Moved some code to getValueStatic.
        (WebCore::PluginView::init):
        * plugins/npapi.cpp: Call PluginView::userAgentStatic
        and PluginView::getValueStatic if no PluginView is
        present.
        (NPN_UserAgent):
        (NPN_GetValue):
        * plugins/qt/PluginPackageQt.cpp:
        (WebCore::PluginPackage::fetchInfo): Corrected split args because ignoring
        empty entries crashed.
        (WebCore::PluginPackage::load): Resolve all symbols when loading plugins
        to protect against XPCOM dependencies.
        * plugins/qt/PluginViewQt.cpp: Add additional currentPluginView guards and
        some small style changes.
        (WebCore::PluginView::updateWindow):
        (WebCore::PluginView::setNPWindowRect):
        (WebCore::PluginView::stop):
        (WebCore::PluginView::userAgentStatic): Added to deal with plugins
        that query this before having a PluginView.
        (WebCore::PluginView::handlePostReadFile):
        (WebCore::PluginView::getValueStatic): Added to deal with plugins
        that call this before we have created a PluginView.
        (WebCore::PluginView::getValue): Moved some code to getValueStatic.
        (WebCore::PluginView::init): m_needsXEmbed init was moved to constructor.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@33570 268f45cc-cd09-0410-ab3c-d52691b4dbfc