Bug 1735212 - Support GPC on Workers; r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D161454

dom/security/test/general/test_gpc.html

@@ -12,12 +12,18 @@ add_task(async function testGlobalPrivacyControlDisabled() {
   await SpecialPowers.pushPrefEnv({ set: [
     ["privacy.globalprivacycontrol.enabled", false],
     ["privacy.globalprivacycontrol.functionality.enabled", true],
-  ]});
-  await fetch("file_gpc_server.sjs")
+  ]})
+  .then(() => fetch("file_gpc_server.sjs"))
   .then((response) => response.text())
   .then((response) => {
     is(response, "false", "GPC disabled so header unsent");
     is(navigator.globalPrivacyControl, false, "GPC disabled so navigator property is 0");
+
+    let worker = new Worker(window.URL.createObjectURL(new Blob(["postMessage(navigator.globalPrivacyControl);"])));
+    return new Promise((resolve) => { worker.onmessage = (e) => { resolve(e.data) } });
+  })
+  .then((response) => {
+    is(response, false, "GPC disabled so worker's navigator property is 0");
   });
 });
 
@@ -25,12 +31,18 @@ add_task(async function testGlobalPrivacyControlEnabled() {
   await SpecialPowers.pushPrefEnv({ set: [
     ["privacy.globalprivacycontrol.enabled", true],
     ["privacy.globalprivacycontrol.functionality.enabled", true],
-  ]});
-  await fetch("file_gpc_server.sjs")
+  ]})
+  .then(() => fetch("file_gpc_server.sjs"))
   .then((response) => response.text())
   .then((response) => {
     is(response, "true", "GPC enabled so header sent and received");
     is(navigator.globalPrivacyControl, true, "GPC enabled so navigator property is 1");
+
+    let worker = new Worker(window.URL.createObjectURL(new Blob(["postMessage(navigator.globalPrivacyControl);"])));
+    return new Promise((resolve) => { worker.onmessage = (e) => { resolve(e.data) } });
+  })
+  .then((response) => {
+    is(response, true, "GPC enabled so worker's navigator property is 1");
   });
 });
 

dom/webidl/Navigator.webidl

@@ -41,6 +41,7 @@ Navigator includes NavigatorConcurrentHardware;
 Navigator includes NavigatorStorage;
 Navigator includes NavigatorAutomationInformation;
 Navigator includes GPUProvider;
+Navigator includes GlobalPrivacyControl;
 
 interface mixin NavigatorID {
   // WebKit/Blink/Trident/Presto support this (hardcoded "Mozilla").
@@ -119,7 +120,7 @@ partial interface Navigator {
 };
 
 // https://globalprivacycontrol.github.io/gpc-spec/
-partial interface Navigator {
+interface mixin GlobalPrivacyControl {
   [Pref="privacy.globalprivacycontrol.functionality.enabled"]
   readonly attribute boolean globalPrivacyControl;
 };

dom/webidl/WorkerNavigator.webidl

@@ -12,6 +12,7 @@ WorkerNavigator includes NavigatorLanguage;
 WorkerNavigator includes NavigatorOnLine;
 WorkerNavigator includes NavigatorConcurrentHardware;
 WorkerNavigator includes NavigatorStorage;
+WorkerNavigator includes GlobalPrivacyControl;
 
 // http://wicg.github.io/netinfo/#extensions-to-the-navigator-interface
 [Exposed=Worker]

dom/workers/WorkerNavigator.h

@@ -14,6 +14,7 @@
 #include "mozilla/RefPtr.h"
 #include "mozilla/dom/BindingDeclarations.h"
 #include "mozilla/dom/workerinternals/RuntimeService.h"
+#include "mozilla/StaticPrefs_privacy.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsISupports.h"
 #include "nsStringFwd.h"
@@ -95,6 +96,11 @@ class WorkerNavigator final : public nsWrapperCache {
   // Worker thread only!
   void SetOnLine(bool aOnline) { mOnline = aOnline; }
 
+  bool GlobalPrivacyControl() const {
+    return StaticPrefs::privacy_globalprivacycontrol_enabled() &&
+           StaticPrefs::privacy_globalprivacycontrol_functionality_enabled();
+  }
+
   void SetLanguages(const nsTArray<nsString>& aLanguages);
 
   uint64_t HardwareConcurrency() const;

modules/libpref/init/StaticPrefList.yaml

@@ -12728,7 +12728,7 @@
 # true - Send the header with a value of 1 to indicate opting-out
 # false - Do not send header to indicate opting-in
 - name: privacy.globalprivacycontrol.enabled
-  type: bool
+  type: RelaxedAtomicBool
   value: false
   mirror: always
 
@@ -12736,7 +12736,7 @@
 # of 'undecided' by leaving the navigator property undefined and not attaching
 # the Sec-GPC HTTP header.
 - name: privacy.globalprivacycontrol.functionality.enabled
-  type: bool
+  type: RelaxedAtomicBool
   value: false
   mirror: always