It appears that the official chrome webstore extension by Rob W is outdated. It was last updated in 2019. 

gulp.dest(CHROME_BUILD_CONTENT_DIR + "build")
        ),
        createWorkerBundle(defines).pipe(
          gulp.dest(CHROME_BUILD_CONTENT_DIR + "build")
        ),
        createSandboxBundle(defines).pipe(
          gulp.dest(CHROME_BUILD_CONTENT_DIR + "build")
        ),
        createWebBundle(defines, { defaultPreferencesDir: "chromium/" }).pipe(
          gulp.dest(CHROME_BUILD_CONTENT_DIR + "web")
        ),
        gulp
          .src(CHROME_WEB_FILES, { base: "web/" })
          .pipe(gulp.dest(CHROME_BUILD_CONTENT_DIR + "web")),
        gulp
          .src(
            ["web/locale/*/viewer.properties", "web/locale/locale.properties"],
            { base: "web/" }
          )
          .pipe(gulp.dest(CHROME_BUILD_CONTENT_DIR + "web")),
        createCMapBundle().pipe(
          gulp.dest(CHROME_BUILD_CONTENT_DIR + "web/cmaps")
        ),
        createStandardFontBundle().pipe(
          gulp.dest(CHROME_BUILD_CONTENT_DIR + "web/standard_fonts")
        ),
        preprocessHTML("web/viewer.html", defines).pipe(
          gulp.dest(CHROME_BUILD_CONTENT_DIR + "web")
        ),
        preprocessCSS("web/viewer.css", defines)