Backed out 2 changesets (bug 1575092) for causing Bug 1596556 and Bug 1596556.

Backed out changeset 8dc03b744500 (bug 1575092)
Backed out changeset e28e46ca4a17 (bug 1575092)

dom/ipc/ContentChild.cpp

@@ -1350,17 +1350,7 @@ void ContentChild::InitXPCOM(
 
   ClientManager::Startup();
 
-  // Respecting COOP and COEP requires processing headers in the parent process
-  // in order to choose an appropriate content process, but the workers'
-  // ScriptLoader processes headers in content processes. An intermediary step
-  // that provides security guarantees is to simply never allow SharedWorkers
-  // and ServiceWorkers to exist in a COOP+COEP process. The ultimate goal
-  // is to allow these worker types to be put in such processes based on their
-  // script response headers.
-  // https://bugzilla.mozilla.org/show_bug.cgi?id=1595206
-  if (!IsWebCoopCoepRemoteType(GetRemoteType())) {
-    RemoteWorkerService::Initialize();
-  }
+  RemoteWorkerService::Initialize();
 
   nsCOMPtr<nsIConsoleService> svc(do_GetService(NS_CONSOLESERVICE_CONTRACTID));
   if (!svc) {

dom/ipc/ContentParent.cpp

@@ -728,11 +728,6 @@ bool IsWebRemoteType(const nsAString& aContentProcessType) {
                           NS_LITERAL_STRING(DEFAULT_REMOTE_TYPE));
 }
 
-bool IsWebCoopCoepRemoteType(const nsAString& aContentProcessType) {
-  return StringBeginsWith(aContentProcessType,
-                          NS_LITERAL_STRING(WITH_COOP_COEP_REMOTE_TYPE_PREFIX));
-}
-
 /*static*/
 uint32_t ContentParent::GetMaxProcessCount(
     const nsAString& aContentProcessType) {

dom/ipc/ContentParent.h

@@ -1398,8 +1398,6 @@ const nsDependentSubstring RemoteTypePrefix(
 // This is based on isWebRemoteType in E10SUtils.jsm.
 bool IsWebRemoteType(const nsAString& aContentProcessType);
 
-bool IsWebCoopCoepRemoteType(const nsAString& aContentProcessType);
-
 }  // namespace dom
 }  // namespace mozilla
 

dom/workers/remoteworkers/RemoteWorkerManager.cpp

@@ -239,12 +239,7 @@ RemoteWorkerManager::SelectTargetActorForServiceWorker(
     auto scopeExit = MakeScopeExit(
         [&] { contentParents.AppendElement(std::move(contentParent)); });
 
-    const nsAString& remoteType = contentParent->GetRemoteType();
-    MOZ_DIAGNOSTIC_ASSERT(
-        !IsWebCoopCoepRemoteType(remoteType),
-        "COOP+COEP processes don't support remote workers right now");
-
-    if (IsWebRemoteType(remoteType)) {
+    if (IsWebRemoteType(contentParent->GetRemoteType())) {
       auto lock = contentParent->mRemoteWorkerActorData.Lock();
 
       if (lock->mCount || !lock->mShutdownStarted) {