Reviewed by Sam Weinig.

        Pass the PSN of the client to the host, and get the PSN of the host back when checking in.
        
        * Plugins/Hosted/NetscapePluginHostManager.h:
        * Plugins/Hosted/NetscapePluginHostManager.mm:
        (WebKit::NetscapePluginHostManager::hostForPackage):
        Get the current PSN and pass it to spawnPluginHost.
        
        (WebKit::NetscapePluginHostManager::spawnPluginHost):
        Pass the PSN to the "check in" function.
        
        * Plugins/Hosted/NetscapePluginHostProxy.h:
        * Plugins/Hosted/NetscapePluginHostProxy.mm:
        (WebKit::NetscapePluginHostProxy::NetscapePluginHostProxy):
        
        (WebKit::NetscapePluginHostProxy::pluginHostDied):
        Fix a bug noticed by Julien Chaffraix. Call endModal if necessary.
        
        (WebKit::NetscapePluginHostProxy::beginModal):
        (WebKit::NetscapePluginHostProxy::endModal):
        (WebKit::NetscapePluginHostProxy::setModal):
        Split out the code that does all of the work into beginModal and endModal methods.
        
        * Plugins/Hosted/WebKitPluginHost.defs:
        * Plugins/WebNetscapePluginView.mm:
        (-[WebNetscapePluginView loadStream]):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@40377 268f45cc-cd09-0410-ab3c-d52691b4dbfc