Bug 1574963 - Add a policy for using legacy profiles on Windows. r=mossop

Differential Revision: https://phabricator.services.mozilla.com/D47841

--HG--
extra : moz-landing-system : lando

browser/components/enterprisepolicies/Policies.jsm

@@ -942,6 +942,10 @@ var Policies = {
     },
   },
 
+  LegacyProfiles: {
+    // Handled in nsToolkitProfileService.cpp (Windows only)
+  },
+
   LocalFileLinks: {
     onBeforeAddons(manager, param) {
       // If there are existing capabilities, lock them with the policy pref.

browser/components/enterprisepolicies/schemas/policies-schema.json

@@ -477,6 +477,10 @@
       }
     },
 
+    "LegacyProfiles": {
+      "type": "boolean"
+    },
+
     "LocalFileLinks": {
       "type": "array",
       "items": {

toolkit/profile/nsToolkitProfileService.cpp

@@ -14,6 +14,7 @@
 #ifdef XP_WIN
 #  include <windows.h>
 #  include <shlobj.h>
+#  include "mozilla/PolicyChecks.h"
 #endif
 #ifdef XP_UNIX
 #  include <unistd.h>
@@ -1797,9 +1798,12 @@ bool nsToolkitProfileService::IsSnapEnvironment() {
  * application versions to different locations, some application sandboxing
  * systems as well as enterprise deployments. This environment variable provides
  * a way to opt out of dedicated profiles for these cases.
+ *
+ * For Windows, we provide a policy to accomplish the same thing.
  */
 bool nsToolkitProfileService::UseLegacyProfiles() {
-  return !!PR_GetEnv("MOZ_LEGACY_PROFILES");
+  return !!PR_GetEnv("MOZ_LEGACY_PROFILES") ||
+         PolicyCheckBoolean(L"LegacyProfiles");
 }
 
 struct FindInstallsClosure {