npapi plugins: Make sure WebPlugin has no key functions on mac.

webkit/plugins/npapi/webplugin_impl.cc

Index: webkit/plugins/npapi/webplugin_impl.cc
diff --git a/webkit/plugins/npapi/webplugin_impl.cc b/webkit/plugins/npapi/webplugin_impl.cc
index 3fe5d1f5c0234ae1ad4016512c62978b403a43f8..cc6177f7df254d027b55e51c4c8fbc48fc3639e0 100644
--- a/webkit/plugins/npapi/webplugin_impl.cc
+++ b/webkit/plugins/npapi/webplugin_impl.cc
@@ -754,6 +754,11 @@ void WebPluginImpl::URLRedirectResponse(bool allow, int resource_id) {
 }
 
 #if defined(OS_MACOSX)
+WebPluginAcceleratedSurface* WebPluginImpl::GetAcceleratedSurface(
+    gfx::GpuPreference gpu_preference) {
+  return NULL;
+}
+
 void WebPluginImpl::AcceleratedPluginEnabledRendering() {
 }