Add a referrer to the Advanced Protection Program URL

So that we can attribute new Advanced Protection users to the
newly added entrypoint.

Bug: 1032584
Change-Id: I8f8a9a6c17008fb25843c89133a08c9cc2362ef6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2080483Reviewed-by: Theodore Olsauskas-Warren <sauski@google.com>
Reviewed-by: dpapad <dpapad@chromium.org>
Commit-Queue: Martin Šrámek <msramek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747933}

chrome/browser/resources/settings/privacy_page/security_page.js

@@ -108,7 +108,7 @@ Polymer({
 
   /** @private */
   onAdvancedProtectionProgramLinkClick_() {
-    window.open('https://landing.google.com/advancedprotection/');
+    window.open(loadTimeData.getString('advancedProtectionURL'));
   },
 
   /** @private */

chrome/browser/ui/webui/settings/settings_localized_strings_provider.cc

@@ -1222,6 +1222,19 @@ void AddPrivacyStrings(content::WebUIDataSource* html_source,
           IDS_SETTINGS_SAFETY_CHECK_SAFE_BROWSING_SUB_LABEL_DISABLED_BY_ADMIN,
           base::ASCIIToUTF16(chrome::kWhoIsMyAdministratorHelpURL)));
 
+  // The link to the Advanced Protection Program landing page, with a referrer
+  // from Chrome settings.
+  GURL advanced_protection_url(
+      "https://landing.google.com/advancedprotection/");
+  advanced_protection_url = net::AppendQueryParameter(advanced_protection_url,
+                                                      "utm_source", "Chrome");
+  advanced_protection_url = net::AppendQueryParameter(
+      advanced_protection_url, "utm_medium", "ChromeSecuritySettings");
+  advanced_protection_url = net::AppendQueryParameter(
+      advanced_protection_url, "utm_campaign", "ChromeSettings");
+  html_source->AddString("advancedProtectionURL",
+                         advanced_protection_url.spec());
+
   AddPersonalizationOptionsStrings(html_source);
 }