diff --git a/utils/doclint/SourceFactory.js b/utils/doclint/Source.js
similarity index 71%
rename from utils/doclint/SourceFactory.js
rename to utils/doclint/Source.js
index 61556274725..455f4192437 100644
--- a/utils/doclint/SourceFactory.js
+++ b/utils/doclint/Source.js
@@ -82,44 +82,19 @@ class Source {
   hasUpdatedText() {
     return this._hasUpdatedText;
   }
-}
 
-class SourceFactory {
-  constructor() {
-    this._sources = new Map();
-  }
-
-  /**
-   * @return {!Array<!Source>}
-   */
-  sources() {
-    return Array.from(this._sources.values());
-  }
-
-  /**
-   * @return {!Promise<boolean>}
-   */
-  async saveChangedSources() {
-    const changedSources = Array.from(this._sources.values()).filter(source => source.hasUpdatedText());
-    if (!changedSources.length)
-      return false;
-    await Promise.all(changedSources.map(source => writeFileAsync(source.filePath(), source.text())));
-    return true;
+  async save() {
+    await writeFileAsync(this.filePath(), this.text());
   }
 
   /**
    * @param {string} filePath
    * @return {!Promise<Source>}
    */
-  async readFile(filePath) {
+  static async readFile(filePath) {
     filePath = path.resolve(filePath);
-    let source = this._sources.get(filePath);
-    if (!source) {
-      const text = await readFileAsync(filePath, {encoding: 'utf8'});
-      source = new Source(filePath, text);
-      this._sources.set(filePath, source);
-    }
-    return source;
+    const text = await readFileAsync(filePath, {encoding: 'utf8'});
+    return new Source(filePath, text);
   }
 
   /**
@@ -127,21 +102,13 @@ class SourceFactory {
    * @param {string=} extension
    * @return {!Promise<!Array<!Source>>}
    */
-  async readdir(dirPath, extension = '') {
+  static async readdir(dirPath, extension = '') {
     const fileNames = await readdirAsync(dirPath);
     const filePaths = fileNames.filter(fileName => fileName.endsWith(extension)).map(fileName => path.join(dirPath, fileName));
-    return Promise.all(filePaths.map(filePath => this.readFile(filePath)));
-  }
-
-  /**
-   * @param {string} filePath
-   * @param {string} text
-   * @return {!Source}
-   */
-  createForTest(filePath, text) {
-    return new Source(filePath, text);
+    return Promise.all(filePaths.map(filePath => Source.readFile(filePath)));
   }
 }
+module.exports = Source;
 
 /**
  * @param {function(?)} nodeFunction
@@ -166,4 +133,3 @@ function promisify(nodeFunction) {
   };
 }
 
-module.exports = SourceFactory;
diff --git a/utils/doclint/check_public_api/test/test.js b/utils/doclint/check_public_api/test/test.js
index dd716aeaf4c..61a49dde68d 100644
--- a/utils/doclint/check_public_api/test/test.js
+++ b/utils/doclint/check_public_api/test/test.js
@@ -17,7 +17,7 @@
 const path = require('path');
 const puppeteer = require('../../../..');
 const checkPublicAPI = require('..');
-const SourceFactory = require('../../SourceFactory');
+const Source = require('../../Source');
 const mdBuilder = require('../MDBuilder');
 const jsBuilder = require('../JSBuilder');
 const GoldenUtils = require('../../../../test/golden-utils');
@@ -64,9 +64,8 @@ async function testLint(state, test) {
     toBeGolden: GoldenUtils.compare.bind(null, dirPath, dirPath)
   });
 
-  const factory = new SourceFactory();
-  const mdSources = await factory.readdir(dirPath, '.md');
-  const jsSources = await factory.readdir(dirPath, '.js');
+  const mdSources = await Source.readdir(dirPath, '.md');
+  const jsSources = await Source.readdir(dirPath, '.js');
   const messages = await checkPublicAPI(page, mdSources, jsSources);
   const errors = messages.map(message => message.text);
   expect(errors.join('\n')).toBeGolden('result.txt');
@@ -77,8 +76,7 @@ async function testMDBuilder(state, test) {
   const {expect} = new Matchers({
     toBeGolden: GoldenUtils.compare.bind(null, dirPath, dirPath)
   });
-  const factory = new SourceFactory();
-  const sources = await factory.readdir(dirPath, '.md');
+  const sources = await Source.readdir(dirPath, '.md');
   const {documentation} = await mdBuilder(page, sources);
   expect(serialize(documentation)).toBeGolden('result.txt');
 }
@@ -88,8 +86,7 @@ async function testJSBuilder(state, test) {
   const {expect} = new Matchers({
     toBeGolden: GoldenUtils.compare.bind(null, dirPath, dirPath)
   });
-  const factory = new SourceFactory();
-  const sources = await factory.readdir(dirPath, '.js');
+  const sources = await Source.readdir(dirPath, '.js');
   const {documentation} = await jsBuilder(sources);
   expect(serialize(documentation)).toBeGolden('result.txt');
 }
diff --git a/utils/doclint/cli.js b/utils/doclint/cli.js
index 296b05f48ad..19b591f81b0 100755
--- a/utils/doclint/cli.js
+++ b/utils/doclint/cli.js
@@ -17,7 +17,7 @@
 
 const puppeteer = require('../..');
 const path = require('path');
-const SourceFactory = require('./SourceFactory');
+const Source = require('./Source');
 
 const PROJECT_DIR = path.join(__dirname, '..', '..');
 const VERSION = require(path.join(PROJECT_DIR, 'package.json')).version;
@@ -31,13 +31,13 @@ run();
 async function run() {
   const startTime = Date.now();
 
-  const sourceFactory = new SourceFactory();
   /** @type {!Array<!Message>} */
   const messages = [];
+  let changedFiles = false;
 
   // Documentation checks.
   {
-    const apiSource = await sourceFactory.readFile(path.join(PROJECT_DIR, 'docs', 'api.md'));
+    const apiSource = await Source.readFile(path.join(PROJECT_DIR, 'docs', 'api.md'));
     const mdSources = [apiSource];
 
     const toc = require('./toc');
@@ -49,9 +49,16 @@ async function run() {
     const browser = await puppeteer.launch({args: ['--no-sandbox']});
     const page = await browser.newPage();
     const checkPublicAPI = require('./check_public_api');
-    const jsSources = await sourceFactory.readdir(path.join(PROJECT_DIR, 'lib'), '.js');
+    const jsSources = await Source.readdir(path.join(PROJECT_DIR, 'lib'), '.js');
     messages.push(...await checkPublicAPI(page, mdSources, jsSources));
     await browser.close();
+
+    for (const source of mdSources) {
+      if (!source.hasUpdatedText())
+        continue;
+      await source.save();
+      changedFiles = true;
+    }
   }
 
   // Report results.
@@ -74,7 +81,7 @@ async function run() {
     }
   }
   let clearExit = messages.length === 0;
-  if (await sourceFactory.saveChangedSources()) {
+  if (changedFiles) {
     if (clearExit)
       console.log(`${YELLOW_COLOR}Some files were updated.${RESET_COLOR}`);
     clearExit = false;
diff --git a/utils/doclint/preprocessor/test.js b/utils/doclint/preprocessor/test.js
index 41401c63bef..26c80c71d86 100644
--- a/utils/doclint/preprocessor/test.js
+++ b/utils/doclint/preprocessor/test.js
@@ -15,9 +15,7 @@
  */
 
 const preprocessor = require('.');
-const SourceFactory = require('../SourceFactory');
-const factory = new SourceFactory();
-
+const Source = require('../Source');
 const {TestRunner, Reporter, Matchers}  = require('../../testrunner/');
 const runner = new TestRunner();
 new Reporter(runner);
@@ -29,7 +27,7 @@ const {expect} = new Matchers();
 
 describe('preprocessor', function() {
   it('should throw for unknown command', function() {
-    const source = factory.createForTest('doc.md', `
+    const source = new Source('doc.md', `
       <!-- gen:unknown-command -->something<!-- gen:stop -->
     `);
     const messages = preprocessor([source], '1.1.1');
@@ -40,7 +38,7 @@ describe('preprocessor', function() {
   });
   describe('gen:version', function() {
     it('should work', function() {
-      const source = factory.createForTest('doc.md', `
+      const source = new Source('doc.md', `
         Puppeteer <!-- gen:version -->XXX<!-- gen:stop -->
       `);
       const messages = preprocessor([source], '1.2.0');
@@ -52,7 +50,7 @@ describe('preprocessor', function() {
       `);
     });
     it('should work for *-post versions', function() {
-      const source = factory.createForTest('doc.md', `
+      const source = new Source('doc.md', `
         Puppeteer <!-- gen:version -->XXX<!-- gen:stop -->
       `);
       const messages = preprocessor([source], '1.2.0-post');
@@ -64,13 +62,13 @@ describe('preprocessor', function() {
       `);
     });
     it('should tolerate different writing', function() {
-      const source = factory.createForTest('doc.md', `Puppeteer v<!--   gEn:version -->WHAT
+      const source = new Source('doc.md', `Puppeteer v<!--   gEn:version -->WHAT
 <!--     GEN:stop   -->`);
       preprocessor([source], '1.1.1');
       expect(source.text()).toBe(`Puppeteer v<!--   gEn:version -->v1.1.1<!--     GEN:stop   -->`);
     });
     it('should not tolerate missing gen:stop', function() {
-      const source = factory.createForTest('doc.md', `<!--GEN:version-->`);
+      const source = new Source('doc.md', `<!--GEN:version-->`);
       const messages = preprocessor([source], '1.2.0');
       expect(source.hasUpdatedText()).toBe(false);
       expect(messages.length).toBe(1);
@@ -80,7 +78,7 @@ describe('preprocessor', function() {
   });
   describe('gen:empty-if-release', function() {
     it('should clear text when release version', function() {
-      const source = factory.createForTest('doc.md', `
+      const source = new Source('doc.md', `
         <!-- gen:empty-if-release -->XXX<!-- gen:stop -->
       `);
       const messages = preprocessor([source], '1.1.1');
@@ -92,7 +90,7 @@ describe('preprocessor', function() {
       `);
     });
     it('should keep text when non-release version', function() {
-      const source = factory.createForTest('doc.md', `
+      const source = new Source('doc.md', `
         <!-- gen:empty-if-release -->XXX<!-- gen:stop -->
       `);
       const messages = preprocessor([source], '1.1.1-post');
@@ -103,7 +101,7 @@ describe('preprocessor', function() {
     });
   });
   it('should work with multiple commands', function() {
-    const source = factory.createForTest('doc.md', `
+    const source = new Source('doc.md', `
       <!-- gen:version -->XXX<!-- gen:stop -->
       <!-- gen:empty-if-release -->YYY<!-- gen:stop -->
       <!-- gen:version -->ZZZ<!-- gen:stop -->