code: function main() {
    var wtfOptions = self.options.wtfOptions || {};
  
    setupCommunications();
  
    injectScriptFile(
        'wtf_trace_web_js_compiled.js', self.options.wtfScriptContents);
    injectScriptFunction(function(options) {
      wtf.trace.prepare(options);
    }, [
      wtfOptions
    ]);
    injectScriptFunction(startTracing, []);
  }
docs: Injects the extension, if needed.
  This is called on startup in the content-script context.