diff --git a/.circleci/config.yml b/.circleci/config.yml
index bd68b8b4ff..ed6f77d700 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -220,7 +220,7 @@ jobs:
               git config user.name "angular-ci"
               git config user.email "angular-ci"
               # Rebase PR on top of target branch.
-              node tools/rebase-pr.js
+              node .circleci/rebase-pr.js
             else
               echo "This build is not over a PR, nothing to do."
             fi
diff --git a/.circleci/rebase-pr.js b/.circleci/rebase-pr.js
new file mode 100644
index 0000000000..085ab4398d
--- /dev/null
+++ b/.circleci/rebase-pr.js
@@ -0,0 +1,207 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+/**
+ * Rebases the current branch on top of the GitHub PR target branch.
+ *
+ * **Context:**
+ * Since a GitHub PR is not necessarily up to date with its target branch, it is useful to rebase
+ * prior to testing it on CI to ensure more up to date test results.
+ *
+ * **NOTE:**
+ * This script cannot use external dependencies or be compiled because it needs to run before the
+ * environment is setup.
+ * Use only features supported by the NodeJS versions used in the environment.
+ */
+// tslint:disable:no-console
+const {execSync} = require('child_process');
+
+
+/** A regex to select a ref that matches our semver refs. */
+const semverRegex = /^(\d+)\.(\d+)\.x$/;
+
+// Run
+_main().catch(err => {
+  console.log('Failed to rebase on top of target branch.\n');
+  console.error(err);
+  process.exitCode = 1;
+});
+
+// Helpers
+async function _main() {
+  const refs = await getRefsAndShasForChange();
+
+  // Log known refs and shas
+  console.log(`--------------------------------`);
+  console.log(`    Target Branch:                   ${refs.base.ref}`);
+  console.log(`    Latest Commit for Target Branch: ${refs.target.latestSha}`);
+  console.log(`    Latest Commit for PR:            ${refs.base.latestSha}`);
+  console.log(`    First Common Ancestor SHA:       ${refs.commonAncestorSha}`);
+  console.log(`--------------------------------`);
+  console.log();
+
+  // Get the count of commits between the latest commit from origin and the common ancestor SHA.
+  const commitCount =
+      exec(`git rev-list --count origin/${refs.base.ref}...${refs.commonAncestorSha}`);
+  console.log(`Checking ${commitCount} commits for changes in the CircleCI config file.`);
+
+  // Check if the files changed between the latest commit from origin and the common ancestor SHA
+  // includes the CircleCI config.
+  const circleCIConfigChanged = exec(`git diff --name-only origin/${refs.base.ref} ${
+      refs.commonAncestorSha} -- .circleci/config.yml`);
+
+  if (!!circleCIConfigChanged) {
+    throw Error(`
+        CircleCI config on ${refs.base.ref} has been modified since commit
+        ${refs.commonAncestorSha.slice(0, 7)}, which this PR is based on.
+
+        Please rebase the PR on ${refs.base.ref} after fetching from upstream.
+
+        Rebase instructions for PR Author, please run the following commands:
+
+          git fetch upstream ${refs.base.ref};
+          git checkout ${refs.target.ref};
+          git rebase upstream/${refs.base.ref};
+          git push --force-with-lease;
+        `);
+  } else {
+    console.log('No change found in the CircleCI config file, continuing.');
+  }
+  console.log();
+
+  // Rebase the PR.
+  exec(`git rebase origin/${refs.base.ref}`);
+  console.log(`Rebased current branch onto ${refs.base.ref}.`);
+}
+
+
+
+/**
+ * Sort a list of fullpath refs into a list and then provide the first entry.
+ *
+ * The sort order will first find master ref, and then any semver ref, followed
+ * by the rest of the refs in the order provided.
+ *
+ * Branches are sorted in this order as work is primarily done on master, and
+ * otherwise on a semver branch. If neither of those were to match, the most
+ * likely correct branch will be the first one encountered in the list.
+ */
+function getRefFromBranchList(gitOutput) {
+  const branches = gitOutput.split('\n').map(b => b.split('/').slice(1).join('').trim());
+  return branches.sort((a, b) => {
+    if (a === 'master') {
+      return -1;
+    }
+    if (b === 'master') {
+      return 1;
+    }
+    const aIsSemver = semverRegex.test(a);
+    const bIsSemver = semverRegex.test(b);
+    if (aIsSemver && bIsSemver) {
+      const [, aMajor, aMinor] = a.match(semverRegex);
+      const [, bMajor, bMinor] = b.match(semverRegex);
+      return parseInt(bMajor, 10) - parseInt(aMajor, 10) ||
+          parseInt(aMinor, 10) - parseInt(bMinor, 10) || 0;
+    }
+    if (aIsSemver) {
+      return -1;
+    }
+    if (bIsSemver) {
+      return 1;
+    }
+    return 0;
+  })[0];
+}
+
+/**
+ * Get the full sha of the ref provided.
+ *
+ * example: 1bc0c1a6c01ede7168f22fa9b3508ba51f1f464e
+ */
+function getShaFromRef(ref) {
+  return exec(`git rev-parse ${ref}`);
+}
+
+/**
+ * Get the list of branches which contain the provided sha, sorted in descending order
+ * by committerdate.
+ *
+ * example:
+ *   upstream/master
+ *   upstream/9.0.x
+ *   upstream/test
+ *   upstream/1.1.x
+ */
+function getBranchListForSha(sha, remote) {
+  return exec(`git branch -r '${remote}/*' --sort=-committerdate --contains ${sha}`);
+}
+
+/** Get the common ancestor sha of the two provided shas. */
+function getCommonAncestorSha(sha1, sha2) {
+  return exec(`git merge-base ${sha1} ${sha2}`);
+}
+
+/**
+ * Adds the remote to git, if it doesn't already exist. Returns a boolean indicating
+ * whether the remote was added by the command.
+ */
+function addAndFetchRemote(owner, name) {
+  const remoteName = `${owner}_${name}`;
+  exec(`git remote add ${remoteName} https://github.com/${owner}/${name}.git`, false);
+  exec(`git fetch ${remoteName}`);
+  return remoteName;
+}
+
+
+/** Get the ref and latest shas for the provided sha on a specific remote. */
+function getRefAndShas(sha, owner, name) {
+  const remoteName = addAndFetchRemote(owner, name);
+
+  // Get the ref on the remote for the sha provided.
+  const branches = getBranchListForSha(sha, remoteName);
+  const ref = getRefFromBranchList(branches);
+
+  // Get the latest sha on the discovered remote ref.
+  const latestSha = getShaFromRef(`${remoteName}/${ref}`);
+
+  return {remote: remoteName, ref, latestSha, sha};
+}
+
+
+/** Gets the refs and shas for the base and target of the current environment. */
+function getRefsAndShasForChange() {
+  const base = getRefAndShas(
+      process.env['CI_GIT_BASE_REVISION'], process.env['CI_REPO_OWNER'],
+      process.env['CI_REPO_NAME']);
+  const target = getRefAndShas(
+      process.env['CI_GIT_REVISION'], process.env['CI_PR_USERNAME'], process.env['CI_PR_REPONAME']);
+  const commonAncestorSha = getCommonAncestorSha(base.sha, target.sha);
+  return {
+    base,
+    target,
+    commonAncestorSha,
+  };
+}
+
+
+/**
+ * Synchronously executes the command.
+ *
+ * Return the trimmed stdout as a string, with an added attribute of the exit code.
+ */
+function exec(command, allowStderr = true) {
+  let output = new String();
+  output.code = 0;
+  try {
+    output += execSync(command, {stdio: ['pipe', 'pipe', 'pipe']}).toString().trim();
+  } catch (err) {
+    allowStderr && console.error(err.stderr.toString());
+    output.code = err.status;
+  }
+  return output;
+}
diff --git a/tools/rebase-pr.js b/tools/rebase-pr.js
deleted file mode 100644
index fe8cf75f73..0000000000
--- a/tools/rebase-pr.js
+++ /dev/null
@@ -1,102 +0,0 @@
-/**
- * @license
- * Copyright Google LLC All Rights Reserved.
- *
- * Use of this source code is governed by an MIT-style license that can be
- * found in the LICENSE file at https://angular.io/license
- */
-
-/**
- * **Usage:**
- * ```
- * node rebase-pr <github-repository> <pull-request-number>
- * ```
- * **Example:**
- * ```
- * node rebase-pr angular/angular 123
- * ```
- *
- * Rebases the current branch on top of the GitHub PR target branch.
- *
- * **Context:**
- * Since a GitHub PR is not necessarily up to date with its target branch, it is useful to rebase
- * prior to testing it on CI to ensure more up to date test results.
- *
- * **Implementation details:**
- * This script obtains the base for a GitHub PR via the
- * [GitHub PR API](https://developer.github.com/v3/pulls/#get-a-single-pull-request), then
- * fetches that branch, and rebases the current branch on top of it.
- *
- * **NOTE:**
- * This script cannot use external dependencies or be compiled because it needs to run before the
- * environment is setup.
- * Use only features supported by the NodeJS versions used in the environment.
- */
-
-// This script uses `console` to print messages to the user.
-// tslint:disable:no-console
-
-// Imports
-const util = require('util');
-const child_process = require('child_process');
-const exec = util.promisify(child_process.exec);
-const getRefsAndShasForChange = require('./utils/git-get-changeset-refs');
-
-
-// Run
-_main().catch(err => {
-  console.log('Failed to rebase on top of target branch.\n');
-  console.error(err);
-  process.exitCode = 1;
-});
-
-// Helpers
-async function _main() {
-  const refs = await getRefsAndShasForChange();
-
-  // Log known refs and shas
-  console.log(`--------------------------------`);
-  console.log(`    Target Branch:                   ${refs.base.ref}`);
-  console.log(`    Latest Commit for Target Branch: ${refs.target.latestSha}`);
-  console.log(`    Latest Commit for PR:            ${refs.base.latestSha}`);
-  console.log(`    First Common Ancestor SHA:       ${refs.commonAncestorSha}`);
-  console.log(`--------------------------------`);
-  console.log();
-
-
-
-  // Get the count of commits between the latest commit from origin and the common ancestor SHA.
-  const {stdout: commitCount} =
-      await exec(`git rev-list --count origin/${refs.base.ref}...${refs.commonAncestorSha}`);
-  console.log(`Checking ${commitCount.trim()} commits for changes in the CircleCI config file.`);
-
-  // Check if the files changed between the latest commit from origin and the common ancestor SHA
-  // includes the CircleCI config.
-  const {stdout: circleCIConfigChanged} = await exec(`git diff --name-only origin/${
-      refs.base.ref} ${refs.commonAncestorSha} -- .circleci/config.yml`);
-
-  if (!!circleCIConfigChanged) {
-    throw Error(`
-        CircleCI config on ${refs.base.ref} has been modified since commit ${
-        refs.commonAncestorSha.slice(0, 7)},
-        which this PR is based on.
-
-        Please rebase the PR on ${refs.base.ref} after fetching from upstream.
-
-        Rebase instructions for PR Author, please run the following commands:
-
-          git fetch upstream ${refs.base.ref};
-          git checkout ${refs.target.ref};
-          git rebase upstream/${refs.base.ref};
-          git push --force-with-lease;
-        `);
-  } else {
-    console.log('No change found in the CircleCI config file, continuing.');
-  }
-  console.log();
-
-  // Rebase the PR.
-  console.log(`Rebasing current branch on ${refs.base.ref}.`);
-  await exec(`git rebase origin/${refs.base.ref}`);
-  console.log('Rebase successful.');
-}
diff --git a/tools/utils/git-get-changeset-refs.js b/tools/utils/git-get-changeset-refs.js
deleted file mode 100644
index a72e5fd798..0000000000
--- a/tools/utils/git-get-changeset-refs.js
+++ /dev/null
@@ -1,181 +0,0 @@
-/**
- * @license
- * Copyright Google LLC All Rights Reserved.
- *
- * Use of this source code is governed by an MIT-style license that can be
- * found in the LICENSE file at https://angular.io/license
- */
-
-const {execSync} = require('child_process');
-
-/** A regex to select a ref that matches our semver refs. */
-const semverRegex = /^(\d+)\.(\d+)\.x$/;
-
-/**
- * Synchronously executes the command.
- *
- * Return the trimmed stdout as a string, with an added attribute of the exit code.
- */
-function exec(command, allowStderr = true) {
-  let output = new String();
-  output.code = 0;
-  try {
-    output += execSync(command, {stdio: ['pipe', 'pipe', 'pipe']}).toString().trim();
-  } catch (err) {
-    allowStderr && console.error(err.stderr.toString());
-    output.code = err.status;
-  }
-  return output;
-}
-
-/**
- * Sort a list of fullpath refs into a list and then provide the first entry.
- *
- * The sort order will first find master ref, and then any semver ref, followed
- * by the rest of the refs in the order provided.
- *
- * Branches are sorted in this order as work is primarily done on master, and
- * otherwise on a semver branch. If neither of those were to match, the most
- * likely correct branch will be the first one encountered in the list.
- */
-function getRefFromBranchList(gitOutput, remote) {
-  const branches = gitOutput.split('\n').map(b => b.split('/').slice(1).join('').trim());
-  return branches.sort((a, b) => {
-    if (a === 'master') {
-      return -1;
-    }
-    if (b === 'master') {
-      return 1;
-    }
-    const aIsSemver = semverRegex.test(a);
-    const bIsSemver = semverRegex.test(b);
-    if (aIsSemver && bIsSemver) {
-      const [, aMajor, aMinor] = a.match(semverRegex);
-      const [, bMajor, bMinor] = b.match(semverRegex);
-      return parseInt(bMajor, 10) - parseInt(aMajor, 10) ||
-          parseInt(aMinor, 10) - parseInt(bMinor, 10) || 0;
-    }
-    if (aIsSemver) {
-      return -1;
-    }
-    if (bIsSemver) {
-      return 1;
-    }
-    return 0;
-  })[0];
-}
-
-/**
- * Get the full sha of the ref provided.
- *
- * example: 1bc0c1a6c01ede7168f22fa9b3508ba51f1f464e
- */
-function getShaFromRef(ref) {
-  return exec(`git rev-parse ${ref}`);
-}
-
-/**
- * Get the list of branches which contain the provided sha, sorted in descending order
- * by committerdate.
- *
- * example:
- *   upstream/master
- *   upstream/9.0.x
- *   upstream/test
- *   upstream/1.1.x
- */
-function getBranchListForSha(sha, remote) {
-  return exec(`git branch -r '${remote}/*' --sort=-committerdate --contains ${sha}`);
-}
-
-/** Get the common ancestor sha of the two provided shas. */
-function getCommonAncestorSha(sha1, sha2) {
-  return exec(`git merge-base ${sha1} ${sha2}`);
-}
-
-/** Removes the remote from git. */
-function removeRemote(remote) {
-  exec(`git remote remove ${remote}`);
-}
-
-/**
- * Adds the remote to git, if it doesn't already exist. Returns a boolean indicating
- * whether the remote was added by the command.
- */
-function addRemote(remote) {
-  return !exec(`git remote add ${remote} https://github.com/${remote}/angular.git`, false).code;
-}
-
-/** Fetch latest from the remote. */
-function fetchRemote(remote) {
-  exec(`git fetch ${remote}`);
-}
-
-/**
- * Get the nearest ref which the HEAD has a parent commit.
- *
- * Checks up to a limit of 100 previous shas.
- */
-function getParentBranchForHead(remote) {
-  // Get the latest for the remote.
-  fetchRemote(remote);
-
-  let headCount = 0;
-  while (headCount < 100) {
-    // Attempt to get the ref on the remote for the sha.
-    const branches = getBranchListForSha(`HEAD~${headCount}`, remote);
-    const ref = getRefFromBranchList(branches, remote);
-    // If the ref exists, get the sha and latest sha for the remote ref.
-    if (ref) {
-      const sha = getShaFromRef(`HEAD~${headCount}`);
-      const latestSha = getShaFromRef(`${remote}/${ref}`);
-      return {ref, sha, latestSha, remote};
-    }
-    headCount++;
-  }
-  return {ref: '', latestSha: '', sha, remote};
-}
-
-/** Get the ref and latest shas for the provided sha on a specific remote. */
-function getRefAndShas(sha, remote) {
-  // Ensure the remote is defined in git.
-  let markRemoteForClean = addRemote(remote);
-  // Get the latest from the remote.
-  fetchRemote(remote);
-
-  // Get the ref on the remote for the sha provided.
-  const branches = getBranchListForSha(sha, remote);
-  const ref = getRefFromBranchList(branches, remote);
-
-  // Get the latest sha on the discovered remote ref.
-  const latestSha = getShaFromRef(`${remote}/${ref}`);
-
-  // Clean up the remote if it didn't exist before execution.
-  if (markRemoteForClean) {
-    removeRemote(remote);
-  }
-
-  return {remote, ref, latestSha, sha};
-}
-
-
-/** Gets the refs and shas for the base and target of the current environment. */
-function getRefsAndShasForChange() {
-  let base, target;
-  if (process.env['CI']) {
-    base = getRefAndShas(process.env['CI_GIT_BASE_REVISION'], process.env['CI_REPO_OWNER']);
-    target = getRefAndShas(process.env['CI_GIT_REVISION'], process.env['CI_PR_USERNAME']);
-  } else {
-    const originSha = getShaFromRef(`HEAD`);
-    target = getRefAndShas(originSha, 'origin');
-    base = getParentBranchForHead('upstream');
-  }
-  const commonAncestorSha = getCommonAncestorSha(base.sha, target.sha);
-  return {
-    base,
-    target,
-    commonAncestorSha,
-  };
-}
-
-module.exports = getRefsAndShasForChange;