Prevent npapi plugin paint when SkPicture based painting is used.

webkit/plugins/npapi/webplugin_delegate_impl_gtk.cc

Index: webkit/plugins/npapi/webplugin_delegate_impl_gtk.cc
diff --git a/webkit/plugins/npapi/webplugin_delegate_impl_gtk.cc b/webkit/plugins/npapi/webplugin_delegate_impl_gtk.cc
index e7d6ff5624e8c96996554dac5b4b22275474e19e..e43b3de739ca1efc2985daaeacd80bd43e8d9a73 100644
--- a/webkit/plugins/npapi/webplugin_delegate_impl_gtk.cc
+++ b/webkit/plugins/npapi/webplugin_delegate_impl_gtk.cc
@@ -110,7 +110,7 @@ void WebPluginDelegateImpl::PlatformDestroyInstance() {
 
 void WebPluginDelegateImpl::Paint(WebKit::WebCanvas* canvas,
                                   const gfx::Rect& rect) {
-  if (!windowless_)
+  if (!windowless_ || !skia::SupportsPlatformPaint(canvas))
     return;
   skia::ScopedPlatformPaint scoped_platform_paint(canvas);
   cairo_t* context = scoped_platform_paint.GetPlatformSurface();