1 files changed, 25 insertions, 0 deletions
diff --git a/mobile/android/modules/geckoview/BrowserUsageTelemetry.jsm b/mobile/android/modules/geckoview/BrowserUsageTelemetry.jsm
new file mode 100644
index 0000000000..a6191d4e57
--- /dev/null
+++ b/mobile/android/modules/geckoview/BrowserUsageTelemetry.jsm
@@ -0,0 +1,25 @@
+/* -*- js-indent-level: 2; indent-tabs-mode: nil -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+var EXPORTED_SYMBOLS = ["getUniqueDomainsVisitedInPast24Hours"];
+
+// Used by nsIBrowserUsage
+function getUniqueDomainsVisitedInPast24Hours() {
+  // The prompting heuristic for the storage access API looks at 1% of the
+  // number of the domains visited in the past 24 hours, with a minimum cap of
+  // 5 domains, in order to prevent prompts from showing up before a tracker is
+  // about to obtain tracking power over a significant portion of the user's
+  // cross-site browsing activity (that is, we do not want to allow automatic
+  // access grants over 1% of the domains). We have the
+  // dom.storage_access.max_concurrent_auto_grants which establishes the
+  // minimum cap here (set to 5 by default) so if we return 0 here the minimum
+  // cap would always take effect. That would only become inaccurate if the
+  // user has browsed more than 500 top-level eTLD's in the past 24 hours,
+  // which should be a very unlikely scenario on mobile anyway.
+
+  return 0;
+}