Show a replacement plug-in for loading errors.

webkit/plugins/ppapi/mock_plugin_delegate.cc

Index: webkit/plugins/ppapi/mock_plugin_delegate.cc
diff --git a/webkit/plugins/ppapi/mock_plugin_delegate.cc b/webkit/plugins/ppapi/mock_plugin_delegate.cc
index 12fe0e73bc5df2f9e0c09cf6661c699b63e154f1..7944ac2aedcbfcf70b3ccb89493787a7c18a6dbc 100644
--- a/webkit/plugins/ppapi/mock_plugin_delegate.cc
+++ b/webkit/plugins/ppapi/mock_plugin_delegate.cc
@@ -50,6 +50,11 @@ SkBitmap* MockPluginDelegate::GetSadPluginBitmap() {
   return NULL;
 }
 
+WebKit::WebPlugin* MockPluginDelegate::CreatePluginReplacement(
+    const FilePath& file_path) {
+  return NULL;
+}
+
 MockPluginDelegate::PlatformImage2D* MockPluginDelegate::CreateImage2D(
     int width,
     int height) {