This is a plugin for Eclipse Orion. The plugin adds a command to the Orion Editor to convert double quotes to single quotes in your JavaScript files. After installing the plugin there will be a new button in the text editor labelled "D2S". When you press it, either the selected text or the entire file will have double quotes converted to single quotes unless otherwise required.
The plugin is based on Esprima and the code from a Ariya Hidayat blog post From double-quotes to single-quotes