nextInlineScriptName_() {
    this.numberInlined_ += 1;
    if (!this.inlineScriptNameBase_) {
      let segments = this.url.split('.');
      segments.pop();
      this.inlineScriptNameBase_ = segments.join('.');
    }
    return this.inlineScriptNameBase_ + '_inline_script_' +
        this.numberInlined_ + '.js';
  }
Invent a name for inline script tags:
@return {string} the page URL, drop .html, add eg "_1.js"