code: function openFileClicked() {
    var inputElement = document.createElement('input');
    inputElement['type'] = 'file';
    inputElement['multiple'] = true;
    inputElement['accept'] = [
      '.wtf-trace,application/x-extension-wtf-trace',
      '.wtf-json,application/x-extension-wtf-json',
      '.wtf-calls,application/x-extension-wtf-calls',
      '.cpuprofile,application/x-extension-cpuprofile',
      '.part,application/x-extension-part'
    ].join(',');
    inputElement.onchange = function(e) {
      _gaq.push(['_trackEvent', 'popup', 'open_file']);
  
      var fileEntries = [];
      for (var n = 0; n < inputElement.files.length; n++) {
        var file = inputElement.files[n];
        var blob = new Blob([file], {
          type: 'application/octet-stream'
        });
        var blobUrl = URL.createObjectURL(blob);
        fileEntries.push({
          name: file.name,
          url: blobUrl,
          size: blob.size
        });
      }
  
      port.postMessage({
        command: 'show_files',
        files: fileEntries
      });
      window.close();
    };
    inputElement.click();
  }
docs: Shows the UI and brings up the open file dialog.