linux: cleanup browser-side GtkSockets when plugins are destroyed

webkit/glue/webview_delegate.h

Index: webkit/glue/webview_delegate.h
diff --git a/webkit/glue/webview_delegate.h b/webkit/glue/webview_delegate.h
index 94fd4f53662641ac8d9a01d8bbd53f0805cb4ee0..b74949c9974f83e3e7a746114e1897da836ab4e9 100644
--- a/webkit/glue/webview_delegate.h
+++ b/webkit/glue/webview_delegate.h
@@ -28,6 +28,7 @@
 
 #include <vector>
 
+#include "base/gfx/native_widget_types.h"
 #include "webkit/api/public/WebNavigationType.h"
 #include "webkit/glue/context_menu.h"
 #include "webkit/glue/webwidget_delegate.h"
@@ -132,6 +133,10 @@ class WebViewDelegate : virtual public WebWidgetDelegate {
     return NULL;
   }
 
+  // Called when a windowed plugin is closing.
+  // Lets the view delegate shut down anything it is using to wrap the plugin.
+  virtual void WillDestroyPluginWindow(gfx::PluginWindowHandle handle) { }
+
   // This method is called when the renderer creates a worker object.
   virtual WebKit::WebWorker* CreateWebWorker(WebKit::WebWorkerClient* client) {
     return NULL;