[SyncSetup]: Add user action when the user click save passphrase.

This CL records a user action when the user clicks on save in the
encryption option in chrome://settings/syncSetup to encrypt data with a
custom passphrase. This metric is needed for sync setup friendly
settings.

Bug: 1050070
Change-Id: I3a8b0e5f9ca0e737172ef7b3206828533733e0f6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2096738Reviewed-by: Esmael Elmoslimany <aee@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Commit-Queue: Monica Basta <msalama@chromium.org>
Cr-Commit-Position: refs/heads/master@{#749630}

chrome/browser/resources/settings/people_page/sync_encryption_options.js

@@ -127,6 +127,7 @@ Polymer({
    */
   saveNewPassphrase_() {
     assert(this.creatingNewPassphrase_);
+    chrome.metricsPrivate.recordUserAction('Sync_SaveNewPassphraseClicked');
     // Might happen within the transient time between the request to
     // |setSyncEncryption| and receiving the response.
     if (this.syncPrefs.encryptAllData) {

tools/metrics/actions/actions.xml

@@ -22582,6 +22582,15 @@ should be able to be added at any place in this file.
   </description>
 </action>
 
+<action name="Sync_SaveNewPassphraseClicked">
+  <owner>msalama@chromium.org</owner>
+  <owner>chrome-signin-team@google.com</owner>
+  <description>
+    The user has clicked on save in the encryption option section from
+    chrome://settings/syncSetup to encrypt the data with a custom passphrase.
+  </description>
+</action>
+
 <action name="Sync_SyncEverything">
   <owner>msalama@chromium.org</owner>
   <owner>chrome-signin-team@google.com</owner>