https://bugs.webkit.org/show_bug.cgi?id=119709
<rdar://problem/14717572>

Reviewed by Anders Carlsson.

* Plugins/Hosted/NetscapePluginHostManager.h:
Add hostLayersInWindowServer argument to instantiatePlugin.

* Plugins/Hosted/NetscapePluginHostManager.mm:
(WebKit::NetscapePluginHostManager::instantiatePlugin):
Add hostLayersInWindowServer argument to instantiatePlugin, and pass it through to WebKitPluginHost.

* Plugins/Hosted/NetscapePluginHostProxy.mm:
(WKPCLayerHostingModeChanged):
Forward the notification that the plugin host changed its layer hosting mode
to the instance proxy.

* Plugins/Hosted/NetscapePluginInstanceProxy.h:
* Plugins/Hosted/NetscapePluginInstanceProxy.mm:
(WebKit::NetscapePluginInstanceProxy::setShouldHostLayersInWindowServer):
Ask the plugin host to re-host its layers when the layer hosting mode changes.

(WebKit::NetscapePluginInstanceProxy::layerHostingModeChanged):
Inform the WebHostedNetscapePluginView of the new layer hosting mode
when it changes. Also, store the new CAContext ID.

* Plugins/Hosted/WebHostedNetscapePluginView.h:
* Plugins/Hosted/WebHostedNetscapePluginView.mm:
(-[WebHostedNetscapePluginView windowHostsLayersInWindowServer]):
Determine whether the WebView's current window uses window-server hosting for its layers.

(-[WebHostedNetscapePluginView createPlugin]):
Drive-by spelling fix.
Factor _pluginLayer initialization out into createPluginLayer.
Instantiate the plugin with the appropriate layer hosting mode.

(-[WebHostedNetscapePluginView createPluginLayer]):

(-[WebHostedNetscapePluginView setHostsLayersInWindowServer:]):
Create a new _pluginLayer if the layer hosting mode changes.
Attach the new _pluginLayer to our parent layer.

(-[WebHostedNetscapePluginView updateAndSetWindow]):
Inform the NetscapePluginInstanceProxy if the layer hosting mode changes,
so it can inform the plugin host. We will asynchronously receive a reply
with the new hosting mode and renderContextID and switch to the new CAContext,
in setHostsLayersInWindowServer:.

* Plugins/Hosted/WebKitPluginClient.defs:
* Plugins/Hosted/WebKitPluginHost.defs:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@154019 268f45cc-cd09-0410-ab3c-d52691b4dbfc