diff --git a/lib/Multimap.js b/lib/Multimap.js
index 78eaba4e704..a1bbd65f3a6 100644
--- a/lib/Multimap.js
+++ b/lib/Multimap.js
@@ -94,13 +94,6 @@ class Multimap {
     this._map.delete(key);
   }
 
-  /**
-   * @return {!Array<K>}
-   */
-  keysArray() {
-    return this._map.keysArray();
-  }
-
   /**
    * @param {K} key
    * @return {?V} value
@@ -124,9 +117,8 @@ class Multimap {
    */
   valuesArray() {
     let result = [];
-    let keys = this.keysArray();
-    for (let i = 0; i < keys.length; ++i)
-      result.pushAll(this.get(keys[i]).valuesArray());
+    for (let key of this._map.keys())
+      result.push(...Array.from(this._map.get(key).values()));
     return result;
   }
 
diff --git a/third_party/chromium/CHANGES.md b/third_party/chromium/CHANGES.md
deleted file mode 100644
index 2a6c8081dd3..00000000000
--- a/third_party/chromium/CHANGES.md
+++ /dev/null
@@ -1,14 +0,0 @@
-Short Name: Chromium
-URL: https://chromium.org
-Version: 484360
-License: The Chromium License
-License File: LICENSE
-Security Critical: no
-
-Description:
-This package is used to get the ESTreeWalker file from Chrome DevTools frontend:
-- ESTreeWalker.js
-
-Local Modifications:
-
-- The "formatterWorker" namespace was removed
diff --git a/third_party/chromium/LICENSE b/third_party/chromium/LICENSE
deleted file mode 100644
index a32e00ce6be..00000000000
--- a/third_party/chromium/LICENSE
+++ /dev/null
@@ -1,27 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//    * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//    * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//    * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/third_party/chromium/ESTreeWalker.js b/utils/doclint/check_public_api/ESTreeWalker.js
similarity index 100%
rename from third_party/chromium/ESTreeWalker.js
rename to utils/doclint/check_public_api/ESTreeWalker.js
diff --git a/utils/doclint/check_public_api/JSBuilder.js b/utils/doclint/check_public_api/JSBuilder.js
index ab8143f8a28..c50376ea19a 100644
--- a/utils/doclint/check_public_api/JSBuilder.js
+++ b/utils/doclint/check_public_api/JSBuilder.js
@@ -15,7 +15,7 @@
  */
 
 const esprima = require('esprima');
-const ESTreeWalker = require('../../../third_party/chromium/ESTreeWalker');
+const ESTreeWalker = require('./ESTreeWalker');
 const Documentation = require('./Documentation');
 
 class JSOutline {