Bug 1905974: Flip closing tabs remotely to default on r=markh

Differential Revision: https://phabricator.services.mozilla.com/D215570

browser/app/profile/firefox.js

@@ -2043,7 +2043,7 @@ pref("identity.fxaccounts.commands.missed.fetch_interval", 86400);
 
 // Controls whether this client can send and receive "close tab"
 // commands from other FxA clients
-pref("identity.fxaccounts.commands.remoteTabManagement.enabled", false);
+pref("identity.fxaccounts.commands.remoteTabManagement.enabled", true);
 
 // Controls whether or not the client association ping has values set on it
 // when the sync-ui-state:update notification fires.

services/fxaccounts/FxAccountsCommands.sys.mjs

@@ -28,6 +28,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
   getRemoteCommandStore: "resource://services-sync/TabsStore.sys.mjs",
   RemoteCommand: "resource://services-sync/TabsStore.sys.mjs",
   Utils: "resource://services-sync/util.sys.mjs",
+  NimbusFeatures: "resource://nimbus/ExperimentAPI.sys.mjs",
 });
 
 XPCOMUtils.defineLazyPreferenceGetter(
@@ -571,15 +572,14 @@ export class CloseRemoteTab extends Command {
     }
   }
 
-  // Returns true if the target device is compatible with closing a tab
-  // XXX - kill this - the pref check is for local stuff, not whether the device is capable!
-  // However, this means moving the pref check into the front-end UI code, which isn't ideal.
+  // Returns true if:
+  // - The target device is compatible with closing a tab (device capability) and
+  // - The local device has the feature enabled locally
   isDeviceCompatible(device) {
-    let pref = Services.prefs.getBoolPref(
-      "identity.fxaccounts.commands.remoteTabManagement.enabled",
-      false
+    return (
+      lazy.NimbusFeatures.remoteTabManagement.getVariable("closeTabsEnabled") &&
+      super.isDeviceCompatible(device)
     );
-    return pref && super.isDeviceCompatible(device);
   }
 
   // Handle incoming remote tab payload, called by FxAccountsCommands.

services/fxaccounts/tests/xpcshell/test_commands_closetab.js

@@ -15,6 +15,12 @@ const { getRemoteCommandStore, RemoteCommand } = ChromeUtils.importESModule(
   "resource://services-sync/TabsStore.sys.mjs"
 );
 
+ChromeUtils.defineESModuleGetters(this, {
+  ExperimentAPI: "resource://nimbus/ExperimentAPI.sys.mjs",
+  ExperimentFakes: "resource://testing-common/NimbusTestUtils.sys.mjs",
+  ExperimentManager: "resource://nimbus/lib/ExperimentManager.sys.mjs",
+});
+
 class TelemetryMock {
   constructor() {
     this._events = [];
@@ -56,21 +62,37 @@ add_task(async function test_closetab_isDeviceCompatible() {
       "https://identity.mozilla.com/cmd/close-uri/v1": "payload",
     },
   };
-  // Even though the command is available, we're keeping this feature behind a feature
-  // flag for now, so it should still show up as "not available"
-  Assert.ok(!closeTab.isDeviceCompatible(device));
-
-  // Enable the feature
-  Services.prefs.setBoolPref(
-    "identity.fxaccounts.commands.remoteTabManagement.enabled",
-    true
-  );
+  // The feature should be on by default
   Assert.ok(closeTab.isDeviceCompatible(device));
 
-  // clear it for the next test
+  // Disable the feature
+  Services.prefs.setBoolPref(
+    "identity.fxaccounts.commands.remoteTabManagement.enabled",
+    false
+  );
+  Assert.ok(!closeTab.isDeviceCompatible(device));
+
+  // clear the pref to test overriding with nimbus
   Services.prefs.clearUserPref(
     "identity.fxaccounts.commands.remoteTabManagement.enabled"
   );
+  Assert.ok(closeTab.isDeviceCompatible(device));
+
+  // Verify that nimbus can remotely override the pref
+  await ExperimentManager.onStartup();
+  await ExperimentAPI.ready();
+  let doExperimentCleanup = await ExperimentFakes.enrollWithFeatureConfig({
+    featureId: "remoteTabManagement",
+    // You can add values for each variable you added to the manifest
+    value: {
+      closeTabsEnabled: false,
+    },
+  });
+
+  // Feature successfully disabled
+  Assert.ok(!closeTab.isDeviceCompatible(device));
+
+  doExperimentCleanup();
 });
 
 add_task(async function test_closetab_send() {

toolkit/components/nimbus/FeatureManifest.yaml

@@ -3346,6 +3346,20 @@ bounceTrackingProtection:
         the feature without risking data loss. Telemetry is still collected
         normally.
 
+remoteTabManagement:
+  description: >
+    Features that let users manage tabs on other devices that are
+    connected to the same Mozilla account.
+  owner: skhamis@mozilla.com
+  hasExposure: false
+  variables:
+    closeTabsEnabled:
+      description: >-
+        When true, the user can close tabs on other devices connected to
+        the same Mozilla account from the synced tabs menu.
+      type: boolean
+      fallbackPref: identity.fxaccounts.commands.remoteTabManagement.enabled
+
 crlite:
   description: Prefs that control the use of CRLite
   owner: jschanck@mozilla.com