From 26f9d5efce138040ec1ce1dd448a747eb7e35caf Mon Sep 17 00:00:00 2001
From: JulianWels <julianwels@mozilla.com>
Date: Thu, 16 Apr 2020 00:33:10 +0000
Subject: [PATCH] Bug 1620244 - Retention telemetry for HTTPS Only Mode.
 r=ckerschb,jcj

Differential Revision: https://phabricator.services.mozilla.com/D69547

--HG--
extra : moz-landing-system : lando
---
 browser/components/BrowserGlue.jsm        | 21 +++++++++++++++++++++
 modules/libpref/init/StaticPrefList.yaml  |  8 ++++++++
 toolkit/components/telemetry/Scalars.yaml | 15 +++++++++++++++
 3 files changed, 44 insertions(+)

diff --git a/browser/components/BrowserGlue.jsm b/browser/components/BrowserGlue.jsm
index fb9c2c51adbc..024051978565 100644
--- a/browser/components/BrowserGlue.jsm
+++ b/browser/components/BrowserGlue.jsm
@@ -1970,6 +1970,26 @@ BrowserGlue.prototype = {
     });
   },
 
+  _monitorHTTPSOnlyPref() {
+    const PREF_ENABLED = "dom.security.https_only_mode";
+    const PREF_WAS_ENABLED = "dom.security.https_only_mode_ever_enabled";
+    const _checkHTTPSOnlyPref = async () => {
+      const enabled = Services.prefs.getBoolPref(PREF_ENABLED, false);
+      const was_enabled = Services.prefs.getBoolPref(PREF_WAS_ENABLED, false);
+      let value = 0;
+      if (enabled) {
+        value = 1;
+        Services.prefs.setBoolPref(PREF_WAS_ENABLED, true);
+      } else if (was_enabled) {
+        value = 2;
+      }
+      Services.telemetry.scalarSet("security.https_only_mode_enabled", value);
+    };
+
+    Services.prefs.addObserver(PREF_ENABLED, _checkHTTPSOnlyPref);
+    _checkHTTPSOnlyPref();
+  },
+
   _showNewInstallModal() {
     // Allow other observers of the same topic to run while we open the dialog.
     Services.tm.dispatchToMainThread(() => {
@@ -2057,6 +2077,7 @@ BrowserGlue.prototype = {
 
     this._monitorScreenshotsPref();
     this._monitorWebcompatReporterPref();
+    this._monitorHTTPSOnlyPref();
 
     let pService = Cc["@mozilla.org/toolkit/profile-service;1"].getService(
       Ci.nsIToolkitProfileService
diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
index cb9770db14aa..ccb08c982a0b 100644
--- a/modules/libpref/init/StaticPrefList.yaml
+++ b/modules/libpref/init/StaticPrefList.yaml
@@ -2454,6 +2454,14 @@
   value: false
   mirror: always
 
+# WARNING: Don't ever update that pref manually! It is only used
+# for telemetry purposes and allows to reason about retention of
+# the pref dom.security.https_only_mode from above.
+- name: dom.security.https_only_mode_ever_enabled
+  type: RelaxedAtomicBool
+  value: false
+  mirror: always
+
 # Is support for selection event APIs enabled?
 - name: dom.select_events.enabled
   type: bool
diff --git a/toolkit/components/telemetry/Scalars.yaml b/toolkit/components/telemetry/Scalars.yaml
index 7fd3819902e6..1cebbc1a9ae1 100644
--- a/toolkit/components/telemetry/Scalars.yaml
+++ b/toolkit/components/telemetry/Scalars.yaml
@@ -758,6 +758,21 @@ security:
       - 'geckoview'
     record_in_processes:
       - main
+  https_only_mode_enabled:
+    bug_numbers:
+      - 1620244
+    description: >
+      Measures user retention of the HTTPS-Only Mode.
+      0 = never enabled, 1 = enabled, 2 = disabled (but was enabled)
+    expires: never
+    kind: uint
+    notification_emails:
+      - julianwels@mozilla.com
+      - seceng-telemetry@mozilla.com
+    products:
+      - 'firefox'
+    record_in_processes:
+      - 'main'
 
 pwmgr:
   potentially_breached_passwords: