Basic windowless plugins, try 2.

webkit/glue/plugins/plugin_instance.cc

Index: webkit/glue/plugins/plugin_instance.cc
diff --git a/webkit/glue/plugins/plugin_instance.cc b/webkit/glue/plugins/plugin_instance.cc
index 9d28592453030845c669b97eeddd5d336443584c..673843595fd68a307b78bea96aefed326e7c85b4 100644
--- a/webkit/glue/plugins/plugin_instance.cc
+++ b/webkit/glue/plugins/plugin_instance.cc
@@ -4,6 +4,11 @@
 
 #include "config.h"
 
+#include "build/build_config.h"
+#if defined(OS_LINUX)
+#define MOZ_X11 1
+#endif
+
 #include "webkit/glue/plugins/plugin_instance.h"
 
 #include "base/file_util.h"
@@ -130,6 +135,12 @@ bool PluginInstance::HandleEvent(UINT message, WPARAM wParam, LPARAM lParam) {
   windowEvent.wParam = static_cast<uint32>(wParam);
   return NPP_HandleEvent(&windowEvent) != 0;
 }
+#elif defined(OS_LINUX)
+bool PluginInstance::HandleEvent(XEvent* event) {
+  if (!windowless_)
+    return false;
+  return NPP_HandleEvent(event);
+}
 #endif
 
 bool PluginInstance::Start(const GURL& url,