Bug 1950564 - QM: Ensure shutdown waits for initialization of all temporary origins to finish; r=dom-storage-reviewers,jstutte

When incremental origin initialization is enabled, shutdown handling in the
quota manager needed improvements to ensure a clean and reliable shutdown
process.

Previously, shutdown could proceed too far while initialization of all
temporary origins in the background was still in progress, potentially leading
to inconsistent states, such as the quota manager joining the QM IO thread
while the initialization was ongoing.

To address this, the existing boolean flag for ongoing initialization is used
to prevent premature shutdown steps while the initialization is still active.

Differential Revision: https://phabricator.services.mozilla.com/D239852

Author: janvarga

dom/quota/ActorsParent.cpp

@@ -2520,18 +2520,23 @@ void QuotaManager::Shutdown() {
   // `isAllClientsShutdownComplete` calls because it should be sufficient
   // to rely on `ShutdownStorage` to abort all existing operations and to
   // wait for all existing directory locks to be released as well.
+  //
+  // This might not be possible after adding mInitializingAllTemporaryOrigins
+  // to the checks below.
 
-  const bool needsToWait =
-      initiateShutdownWorkThreads() || static_cast<bool>(gNormalOriginOps);
+  const bool needsToWait = initiateShutdownWorkThreads() ||
+                           static_cast<bool>(gNormalOriginOps) ||
+                           mInitializingAllTemporaryOrigins;
 
   // If any clients cannot shutdown immediately, spin the event loop while we
   // wait on all the threads to close.
   if (needsToWait) {
     startKillActorsTimer();
 
     MOZ_ALWAYS_TRUE(SpinEventLoopUntil(
-        "QuotaManager::Shutdown"_ns, [isAllClientsShutdownComplete]() {
-          return !gNormalOriginOps && isAllClientsShutdownComplete();
+        "QuotaManager::Shutdown"_ns, [this, isAllClientsShutdownComplete]() {
+          return !gNormalOriginOps && isAllClientsShutdownComplete() &&
+                 !mInitializingAllTemporaryOrigins;
         }));
 
     stopKillActorsTimer();

dom/quota/test/xpcshell/test_shutdownDuringAllTemporaryOriginsInitialization2.js

@@ -167,7 +167,6 @@ async function testSteps() {
         ["dom.quotaManager.loadQuotaFromCache", false],
         ["dom.quotaManager.groupInitialization.pauseOnIOThreadMs", 2000],
       ],
-      skip_if: () => true,
     },
     testShutdownDuringAllTemporaryOriginsInitialization2
   );