1 files changed, 649 insertions, 0 deletions
diff --git a/dom/media/gmp/GMPServiceChild.cpp b/dom/media/gmp/GMPServiceChild.cpp
new file mode 100644
index 0000000000..1d8f399aeb
--- /dev/null
+++ b/dom/media/gmp/GMPServiceChild.cpp
@@ -0,0 +1,649 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GMPServiceChild.h"
+
+#include "GMPLog.h"
+#include "GMPParent.h"
+#include "base/task.h"
+#include "mozIGeckoMediaPluginChromeService.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/SchedulerGroup.h"
+#include "mozilla/StaticMutex.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/SyncRunnable.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/ipc/Endpoint.h"
+#include "nsCOMPtr.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIObserverService.h"
+#include "nsReadableUtils.h"
+#include "nsXPCOMPrivate.h"
+#include "runnable_utils.h"
+
+namespace mozilla::gmp {
+
+#ifdef __CLASS__
+#  undef __CLASS__
+#endif
+#define __CLASS__ "GMPServiceChild"
+
+already_AddRefed<GeckoMediaPluginServiceChild>
+GeckoMediaPluginServiceChild::GetSingleton() {
+  MOZ_ASSERT(!XRE_IsParentProcess());
+  RefPtr<GeckoMediaPluginService> service(
+      GeckoMediaPluginService::GetGeckoMediaPluginService());
+#ifdef DEBUG
+  if (service) {
+    nsCOMPtr<mozIGeckoMediaPluginChromeService> chromeService;
+    CallQueryInterface(service.get(), getter_AddRefs(chromeService));
+    MOZ_ASSERT(!chromeService);
+  }
+#endif
+  return service.forget().downcast<GeckoMediaPluginServiceChild>();
+}
+
+nsresult GeckoMediaPluginServiceChild::Init() {
+  MOZ_ASSERT(NS_IsMainThread());
+  GMP_LOG_DEBUG("%s::%s", __CLASS__, __FUNCTION__);
+
+  nsresult rv = AddShutdownBlocker();
+  if (NS_FAILED(rv)) {
+    MOZ_ASSERT_UNREACHABLE(
+        "We expect xpcom to be live when calling this, so we should be able to "
+        "add a blocker");
+    GMP_LOG_DEBUG("%s::%s failed to add shutdown blocker!", __CLASS__,
+                  __FUNCTION__);
+    return rv;
+  }
+
+  return GeckoMediaPluginService::Init();
+}
+
+NS_IMPL_ISUPPORTS_INHERITED(GeckoMediaPluginServiceChild,
+                            GeckoMediaPluginService, nsIAsyncShutdownBlocker)
+
+// Used to identify blockers that we put in place.
+static const nsLiteralString kShutdownBlockerName =
+    u"GeckoMediaPluginServiceChild: shutdown"_ns;
+
+// nsIAsyncShutdownBlocker members
+NS_IMETHODIMP
+GeckoMediaPluginServiceChild::GetName(nsAString& aName) {
+  aName = kShutdownBlockerName;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+GeckoMediaPluginServiceChild::GetState(nsIPropertyBag**) { return NS_OK; }
+
+NS_IMETHODIMP
+GeckoMediaPluginServiceChild::BlockShutdown(nsIAsyncShutdownClient*) {
+  MOZ_ASSERT(NS_IsMainThread());
+  GMP_LOG_DEBUG("%s::%s", __CLASS__, __FUNCTION__);
+
+  mXPCOMWillShutdown = true;
+
+  MutexAutoLock lock(mMutex);
+  Unused << NS_WARN_IF(NS_FAILED(mGMPThread->Dispatch(
+      NewRunnableMethod("GeckoMediaPluginServiceChild::BeginShutdown", this,
+                        &GeckoMediaPluginServiceChild::BeginShutdown))));
+  return NS_OK;
+}
+// End nsIAsyncShutdownBlocker members
+
+GeckoMediaPluginServiceChild::~GeckoMediaPluginServiceChild() {
+  MOZ_ASSERT(!mServiceChild);
+}
+
+RefPtr<GetGMPContentParentPromise>
+GeckoMediaPluginServiceChild::GetContentParent(
+    GMPCrashHelper* aHelper, const NodeIdVariant& aNodeIdVariant,
+    const nsACString& aAPI, const nsTArray<nsCString>& aTags) {
+  AssertOnGMPThread();
+  MOZ_ASSERT(!mShuttingDownOnGMPThread,
+             "Should not be called if GMPThread is shutting down!");
+
+  MozPromiseHolder<GetGMPContentParentPromise>* rawHolder =
+      new MozPromiseHolder<GetGMPContentParentPromise>();
+  RefPtr<GetGMPContentParentPromise> promise = rawHolder->Ensure(__func__);
+  nsCOMPtr<nsISerialEventTarget> thread(GetGMPThread());
+
+  nsCString api(aAPI);
+  RefPtr<GMPCrashHelper> helper(aHelper);
+  RefPtr<GeckoMediaPluginServiceChild> self(this);
+
+  mPendingGetContentParents += 1;
+
+  GetServiceChild()->Then(
+      thread, __func__,
+      [nodeIdVariant = aNodeIdVariant, self, api, tags = aTags.Clone(), helper,
+       rawHolder](GMPServiceChild* child) {
+        nsTArray<base::ProcessId> alreadyBridgedTo;
+
+        // We want to force the content process to keep all of our
+        // GMPContentParent IPDL objects alive while we wait to resolve which
+        // process can satisfy our request. This avoids a race condition where
+        // the last dependency is released before we can acquire our own.
+        auto* rawBlockers =
+            new nsTArray<RefPtr<GMPContentParentCloseBlocker>>();
+        child->GetAndBlockAlreadyBridgedTo(alreadyBridgedTo, *rawBlockers);
+
+        child->SendLaunchGMP(
+            nodeIdVariant, api, tags, alreadyBridgedTo,
+            [rawHolder, self, helper, rawBlockers,
+             child = RefPtr{child}](GMPLaunchResult&& aResult) {
+              UniquePtr<MozPromiseHolder<GetGMPContentParentPromise>> holder(
+                  rawHolder);
+              UniquePtr<nsTArray<RefPtr<GMPContentParentCloseBlocker>>>
+                  blockers(rawBlockers);
+              if (helper && aResult.pluginId()) {
+                // Note: Even if the launch failed, we need to connect the crash
+                // helper so that if the launch failed due to the plugin
+                // crashing, we can report the crash via the crash reporter. The
+                // crash handling notification will arrive shortly if the launch
+                // failed due to the plugin crashing.
+                self->ConnectCrashHelper(aResult.pluginId(), helper);
+              }
+
+              if (NS_WARN_IF(NS_FAILED(aResult.result()))) {
+                MediaResult error(
+                    aResult.result(),
+                    nsPrintfCString(
+                        "GeckoMediaPluginServiceChild::GetContentParent "
+                        "SendLaunchGMPForNodeId failed with description (%s)",
+                        aResult.errorDescription().get()));
+
+                GMP_LOG_DEBUG("%s failed to launch GMP with error: %s",
+                              __CLASS__, aResult.errorDescription().get());
+                self->mPendingGetContentParents -= 1;
+                self->RemoveShutdownBlockerIfNeeded();
+
+                holder->Reject(error, __func__);
+                return;
+              }
+
+              // If we didn't explicitly fail, we should have been told about a
+              // process running.
+              MOZ_ASSERT(aResult.pid() != base::kInvalidProcessId);
+
+              // It is possible the GMP process may have terminated before we
+              // were able to process this result. In that case, we should just
+              // fail as normal as the initialization of the IPDL objects would
+              // have just failed anyways and produced the same result.
+              bool contains = child->HasAlreadyBridgedTo(aResult.pid());
+              if (NS_WARN_IF(!contains && !aResult.endpoint().IsValid())) {
+                MediaResult error(
+                    aResult.result(),
+                    "GeckoMediaPluginServiceChild::GetContentParent "
+                    "SendLaunchGMPForNodeId failed with process exit"_ns);
+
+                GMP_LOG_DEBUG("%s failed to launch GMP with process exit",
+                              __CLASS__);
+                self->mPendingGetContentParents -= 1;
+                self->RemoveShutdownBlockerIfNeeded();
+
+                holder->Reject(error, __func__);
+                return;
+              }
+
+              RefPtr<GMPContentParent> parent =
+                  child->GetBridgedGMPContentParent(
+                      aResult.pid(), std::move(aResult.endpoint()));
+              if (!contains) {
+                parent->SetDisplayName(aResult.displayName());
+                parent->SetPluginId(aResult.pluginId());
+                parent->SetPluginType(aResult.pluginType());
+              }
+
+              // The content parent is no longer pending.
+              self->mPendingGetContentParents -= 1;
+              MOZ_ASSERT(child->HaveContentParents(),
+                         "We should have at least one content parent!");
+              // We don't check if we need to remove the shutdown blocker here
+              // as we should always have at least one live content parent.
+
+              RefPtr<GMPContentParentCloseBlocker> blocker(
+                  new GMPContentParentCloseBlocker(parent));
+              holder->Resolve(blocker, __func__);
+            },
+            [rawHolder, self, helper,
+             rawBlockers](const ipc::ResponseRejectReason&) {
+              UniquePtr<MozPromiseHolder<GetGMPContentParentPromise>> holder(
+                  rawHolder);
+              UniquePtr<nsTArray<RefPtr<GMPContentParentCloseBlocker>>>
+                  blockers(rawBlockers);
+              MediaResult error(
+                  NS_ERROR_FAILURE,
+                  "GeckoMediaPluginServiceChild::GetContentParent "
+                  "SendLaunchGMPForNodeId failed with IPC error"_ns);
+
+              GMP_LOG_DEBUG("%s failed to launch GMP with IPC error",
+                            __CLASS__);
+              self->mPendingGetContentParents -= 1;
+              self->RemoveShutdownBlockerIfNeeded();
+
+              holder->Reject(error, __func__);
+            });
+      },
+      [self, rawHolder](MediaResult result) {
+        self->mPendingGetContentParents -= 1;
+        self->RemoveShutdownBlockerIfNeeded();
+        UniquePtr<MozPromiseHolder<GetGMPContentParentPromise>> holder(
+            rawHolder);
+        holder->Reject(result, __func__);
+      });
+
+  return promise;
+}
+
+typedef mozilla::dom::GMPCapabilityData GMPCapabilityData;
+typedef mozilla::dom::GMPAPITags GMPAPITags;
+
+struct GMPCapabilityAndVersion {
+  explicit GMPCapabilityAndVersion(const GMPCapabilityData& aCapabilities)
+      : mName(aCapabilities.name()), mVersion(aCapabilities.version()) {
+    for (const GMPAPITags& tags : aCapabilities.capabilities()) {
+      GMPCapability cap;
+      cap.mAPIName = tags.api();
+      for (const nsACString& tag : tags.tags()) {
+        cap.mAPITags.AppendElement(tag);
+      }
+      mCapabilities.AppendElement(std::move(cap));
+    }
+  }
+
+  nsCString ToString() const {
+    nsCString s;
+    s.Append(mName);
+    s.AppendLiteral(" version=");
+    s.Append(mVersion);
+    s.AppendLiteral(" tags=[");
+    StringJoinAppend(s, " "_ns, mCapabilities,
+                     [](auto& tags, const GMPCapability& cap) {
+                       tags.Append(cap.mAPIName);
+                       for (const nsACString& tag : cap.mAPITags) {
+                         tags.AppendLiteral(":");
+                         tags.Append(tag);
+                       }
+                     });
+    s.AppendLiteral("]");
+    return s;
+  }
+
+  nsCString mName;
+  nsCString mVersion;
+  nsTArray<GMPCapability> mCapabilities;
+};
+
+StaticMutex sGMPCapabilitiesMutex;
+StaticAutoPtr<nsTArray<GMPCapabilityAndVersion>> sGMPCapabilities;
+
+static auto GMPCapabilitiesToString() {
+  return StringJoin(", "_ns, *sGMPCapabilities,
+                    [](nsACString& dest, const GMPCapabilityAndVersion& gmp) {
+                      dest.Append(gmp.ToString());
+                    });
+}
+
+/* static */
+void GeckoMediaPluginServiceChild::UpdateGMPCapabilities(
+    nsTArray<GMPCapabilityData>&& aCapabilities) {
+  {
+    // The mutex should unlock before sending the "gmp-changed" observer
+    // service notification.
+    StaticMutexAutoLock lock(sGMPCapabilitiesMutex);
+    if (!sGMPCapabilities) {
+      sGMPCapabilities = new nsTArray<GMPCapabilityAndVersion>();
+      ClearOnShutdown(&sGMPCapabilities);
+    }
+    sGMPCapabilities->Clear();
+    for (const GMPCapabilityData& plugin : aCapabilities) {
+      sGMPCapabilities->AppendElement(GMPCapabilityAndVersion(plugin));
+    }
+
+    GMP_LOG_DEBUG("%s::%s {%s}", __CLASS__, __FUNCTION__,
+                  GMPCapabilitiesToString().get());
+  }
+
+  // Fire a notification so that any MediaKeySystemAccess
+  // requests waiting on a CDM to download will retry.
+  nsCOMPtr<nsIObserverService> obsService =
+      mozilla::services::GetObserverService();
+  MOZ_ASSERT(obsService);
+  if (obsService) {
+    obsService->NotifyObservers(nullptr, "gmp-changed", nullptr);
+  }
+}
+
+void GeckoMediaPluginServiceChild::BeginShutdown() {
+  AssertOnGMPThread();
+  GMP_LOG_DEBUG("%s::%s: mServiceChild=%p,", __CLASS__, __FUNCTION__,
+                mServiceChild.get());
+  // It's possible this gets called twice if the parent sends us a message to
+  // shutdown and we block shutdown in content in close proximity.
+  mShuttingDownOnGMPThread = true;
+  RemoveShutdownBlockerIfNeeded();
+}
+
+NS_IMETHODIMP
+GeckoMediaPluginServiceChild::HasPluginForAPI(const nsACString& aAPI,
+                                              const nsTArray<nsCString>& aTags,
+                                              bool* aHasPlugin) {
+  StaticMutexAutoLock lock(sGMPCapabilitiesMutex);
+  if (!sGMPCapabilities) {
+    *aHasPlugin = false;
+    return NS_OK;
+  }
+
+  nsCString api(aAPI);
+  for (const GMPCapabilityAndVersion& plugin : *sGMPCapabilities) {
+    if (GMPCapability::Supports(plugin.mCapabilities, api, aTags)) {
+      *aHasPlugin = true;
+      return NS_OK;
+    }
+  }
+
+  *aHasPlugin = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+GeckoMediaPluginServiceChild::FindPluginDirectoryForAPI(
+    const nsACString& aAPI, const nsTArray<nsCString>& aTags,
+    nsIFile** aDirectory) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+GeckoMediaPluginServiceChild::GetNodeId(
+    const nsAString& aOrigin, const nsAString& aTopLevelOrigin,
+    const nsAString& aGMPName, UniquePtr<GetNodeIdCallback>&& aCallback) {
+  AssertOnGMPThread();
+
+  GetNodeIdCallback* rawCallback = aCallback.release();
+  nsCOMPtr<nsISerialEventTarget> thread(GetGMPThread());
+  nsString origin(aOrigin);
+  nsString topLevelOrigin(aTopLevelOrigin);
+  nsString gmpName(aGMPName);
+  GetServiceChild()->Then(
+      thread, __func__,
+      [rawCallback, origin, topLevelOrigin, gmpName](GMPServiceChild* child) {
+        child->SendGetGMPNodeId(
+            origin, topLevelOrigin, gmpName,
+            [rawCallback](nsCString&& aId) {
+              UniquePtr<GetNodeIdCallback> callback(rawCallback);
+              callback->Done(NS_OK, aId);
+            },
+            [rawCallback](const ipc::ResponseRejectReason&) {
+              UniquePtr<GetNodeIdCallback> callback(rawCallback);
+              callback->Done(NS_ERROR_FAILURE, ""_ns);
+            });
+      },
+      [rawCallback](nsresult rv) {
+        UniquePtr<GetNodeIdCallback> callback(rawCallback);
+        callback->Done(NS_ERROR_FAILURE, ""_ns);
+      });
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+GeckoMediaPluginServiceChild::Observe(nsISupports* aSubject, const char* aTopic,
+                                      const char16_t* aSomeData) {
+  MOZ_ASSERT(NS_IsMainThread());
+  GMP_LOG_DEBUG("%s::%s: aTopic=%s", __CLASS__, __FUNCTION__, aTopic);
+  if (!strcmp(NS_XPCOM_SHUTDOWN_THREADS_OBSERVER_ID, aTopic)) {
+    if (mServiceChild) {
+      MutexAutoLock lock(mMutex);
+      mozilla::SyncRunnable::DispatchToThread(
+          mGMPThread,
+          WrapRunnable(mServiceChild.get(), &PGMPServiceChild::Close));
+      mServiceChild = nullptr;
+    }
+    ShutdownGMPThread();
+  }
+
+  return NS_OK;
+}
+
+RefPtr<GeckoMediaPluginServiceChild::GetServiceChildPromise>
+GeckoMediaPluginServiceChild::GetServiceChild() {
+  AssertOnGMPThread();
+
+  if (!mServiceChild) {
+    if (mShuttingDownOnGMPThread) {
+      // We have begun shutdown. Don't allow a new connection to the main
+      // process to be instantiated. This also prevents new plugins being
+      // instantiated.
+      return GetServiceChildPromise::CreateAndReject(NS_ERROR_FAILURE,
+                                                     __func__);
+    }
+    dom::ContentChild* contentChild = dom::ContentChild::GetSingleton();
+    if (!contentChild) {
+      return GetServiceChildPromise::CreateAndReject(NS_ERROR_FAILURE,
+                                                     __func__);
+    }
+    MozPromiseHolder<GetServiceChildPromise>* holder =
+        mGetServiceChildPromises.AppendElement();
+    RefPtr<GetServiceChildPromise> promise = holder->Ensure(__func__);
+    if (mGetServiceChildPromises.Length() == 1) {
+      nsCOMPtr<nsIRunnable> r =
+          WrapRunnable(contentChild, &dom::ContentChild::SendCreateGMPService);
+      SchedulerGroup::Dispatch(r.forget());
+    }
+    return promise;
+  }
+  return GetServiceChildPromise::CreateAndResolve(mServiceChild.get(),
+                                                  __func__);
+}
+
+void GeckoMediaPluginServiceChild::SetServiceChild(
+    RefPtr<GMPServiceChild>&& aServiceChild) {
+  AssertOnGMPThread();
+  MOZ_ASSERT(!mServiceChild, "Should not already have service child!");
+  GMP_LOG_DEBUG("%s::%s: aServiceChild=%p", __CLASS__, __FUNCTION__,
+                aServiceChild.get());
+
+  mServiceChild = std::move(aServiceChild);
+
+  nsTArray<MozPromiseHolder<GetServiceChildPromise>> holders =
+      std::move(mGetServiceChildPromises);
+  for (MozPromiseHolder<GetServiceChildPromise>& holder : holders) {
+    holder.Resolve(mServiceChild.get(), __func__);
+  }
+}
+
+void GeckoMediaPluginServiceChild::RemoveGMPContentParent(
+    GMPContentParent* aGMPContentParent) {
+  AssertOnGMPThread();
+  GMP_LOG_DEBUG(
+      "%s::%s: aGMPContentParent=%p, mServiceChild=%p, "
+      "mShuttingDownOnGMPThread=%s",
+      __CLASS__, __FUNCTION__, aGMPContentParent, mServiceChild.get(),
+      mShuttingDownOnGMPThread ? "true" : "false");
+
+  if (mServiceChild) {
+    mServiceChild->RemoveGMPContentParent(aGMPContentParent);
+    GMP_LOG_DEBUG(
+        "%s::%s: aGMPContentParent removed, "
+        "mServiceChild->HaveContentParents()=%s",
+        __CLASS__, __FUNCTION__,
+        mServiceChild->HaveContentParents() ? "true" : "false");
+    RemoveShutdownBlockerIfNeeded();
+  }
+}
+
+nsresult GeckoMediaPluginServiceChild::AddShutdownBlocker() {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!mShuttingDownOnGMPThread,
+             "No call paths should add blockers once we're shutting down!");
+  MOZ_ASSERT(!mShutdownBlockerAdded, "Should only add blocker once!");
+  GMP_LOG_DEBUG("%s::%s ", __CLASS__, __FUNCTION__);
+
+  nsCOMPtr<nsIAsyncShutdownClient> barrier = GetShutdownBarrier();
+  if (NS_WARN_IF(!barrier)) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsresult rv =
+      barrier->AddBlocker(this, NS_LITERAL_STRING_FROM_CSTRING(__FILE__),
+                          __LINE__, kShutdownBlockerName);
+#ifdef DEBUG
+  mShutdownBlockerAdded = NS_SUCCEEDED(rv);
+#endif
+  return rv;
+}
+
+void GeckoMediaPluginServiceChild::RemoveShutdownBlocker() {
+  AssertOnGMPThread();
+  MOZ_ASSERT(mShuttingDownOnGMPThread,
+             "We should only remove blockers once we're "
+             "shutting down!");
+  GMP_LOG_DEBUG("%s::%s ", __CLASS__, __FUNCTION__);
+  nsresult rv = mMainThread->Dispatch(NS_NewRunnableFunction(
+      "GeckoMediaPluginServiceChild::"
+      "RemoveShutdownBlocker",
+      [this, self = RefPtr<GeckoMediaPluginServiceChild>(this)]() {
+        nsCOMPtr<nsIAsyncShutdownClient> barrier = GetShutdownBarrier();
+        if (NS_WARN_IF(!barrier)) {
+          return;
+        }
+
+        nsresult rv = barrier->RemoveBlocker(this);
+        MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+      }));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    MOZ_ASSERT_UNREACHABLE(
+        "Main thread should always be alive when we "
+        "call this!");
+  }
+}
+
+void GeckoMediaPluginServiceChild::RemoveShutdownBlockerIfNeeded() {
+  AssertOnGMPThread();
+  GMP_LOG_DEBUG(
+      "%s::%s mPendingGetContentParents=%" PRIu32
+      " mServiceChild->HaveContentParents()=%s "
+      "mShuttingDownOnGMPThread=%s",
+      __CLASS__, __FUNCTION__, mPendingGetContentParents,
+      mServiceChild && mServiceChild->HaveContentParents() ? "true" : "false",
+      mShuttingDownOnGMPThread ? "true" : "false");
+
+  bool haveOneOrMoreContentParents =
+      mPendingGetContentParents > 0 ||
+      (mServiceChild && mServiceChild->HaveContentParents());
+
+  if (!mShuttingDownOnGMPThread || haveOneOrMoreContentParents) {
+    return;
+  }
+  RemoveShutdownBlocker();
+}
+
+already_AddRefed<GMPContentParent> GMPServiceChild::GetBridgedGMPContentParent(
+    ProcessId aOtherPid, ipc::Endpoint<PGMPContentParent>&& endpoint) {
+  return do_AddRef(mContentParents.LookupOrInsertWith(aOtherPid, [&] {
+    MOZ_ASSERT(aOtherPid == endpoint.OtherPid());
+
+    auto parent = MakeRefPtr<GMPContentParent>();
+
+    DebugOnly<bool> ok = endpoint.Bind(parent);
+    MOZ_ASSERT(ok);
+
+    return parent;
+  }));
+}
+
+void GMPServiceChild::RemoveGMPContentParent(
+    GMPContentParent* aGMPContentParent) {
+  for (auto iter = mContentParents.Iter(); !iter.Done(); iter.Next()) {
+    RefPtr<GMPContentParent>& parent = iter.Data();
+    if (parent == aGMPContentParent) {
+      iter.Remove();
+      break;
+    }
+  }
+}
+
+bool GMPServiceChild::HasAlreadyBridgedTo(base::ProcessId aPid) const {
+  return mContentParents.Contains(aPid);
+}
+
+void GMPServiceChild::GetAndBlockAlreadyBridgedTo(
+    nsTArray<base::ProcessId>& aAlreadyBridgedTo,
+    nsTArray<RefPtr<GMPContentParentCloseBlocker>>& aBlockers) {
+  aAlreadyBridgedTo.SetCapacity(mContentParents.Count());
+  aBlockers.SetCapacity(mContentParents.Count());
+  for (auto iter = mContentParents.Iter(); !iter.Done(); iter.Next()) {
+    aAlreadyBridgedTo.AppendElement(iter.Key());
+    aBlockers.AppendElement(new GMPContentParentCloseBlocker(iter.UserData()));
+  }
+}
+
+class OpenPGMPServiceChild : public mozilla::Runnable {
+ public:
+  OpenPGMPServiceChild(RefPtr<GMPServiceChild>&& aGMPServiceChild,
+                       ipc::Endpoint<PGMPServiceChild>&& aEndpoint)
+      : Runnable("gmp::OpenPGMPServiceChild"),
+        mGMPServiceChild(std::move(aGMPServiceChild)),
+        mEndpoint(std::move(aEndpoint)) {}
+
+  NS_IMETHOD Run() override {
+    RefPtr<GeckoMediaPluginServiceChild> gmp =
+        GeckoMediaPluginServiceChild::GetSingleton();
+    MOZ_RELEASE_ASSERT(gmp);
+    MOZ_ASSERT(!gmp->mServiceChild);
+    if (mEndpoint.Bind(mGMPServiceChild.get())) {
+      gmp->SetServiceChild(std::move(mGMPServiceChild));
+    } else {
+      gmp->SetServiceChild(nullptr);
+    }
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<GMPServiceChild> mGMPServiceChild;
+  ipc::Endpoint<PGMPServiceChild> mEndpoint;
+};
+
+/* static */
+bool GMPServiceChild::Create(Endpoint<PGMPServiceChild>&& aGMPService) {
+  RefPtr<GeckoMediaPluginServiceChild> gmp =
+      GeckoMediaPluginServiceChild::GetSingleton();
+  if (NS_WARN_IF(!gmp)) {
+    return false;
+  }
+
+  MOZ_ASSERT(!gmp->mServiceChild);
+
+  RefPtr<GMPServiceChild> serviceChild(new GMPServiceChild());
+
+  nsCOMPtr<nsIThread> gmpThread;
+  nsresult rv = gmp->GetThread(getter_AddRefs(gmpThread));
+  NS_ENSURE_SUCCESS(rv, false);
+
+  rv = gmpThread->Dispatch(
+      new OpenPGMPServiceChild(std::move(serviceChild), std::move(aGMPService)),
+      NS_DISPATCH_NORMAL);
+  return NS_SUCCEEDED(rv);
+}
+
+ipc::IPCResult GMPServiceChild::RecvBeginShutdown() {
+  RefPtr<GeckoMediaPluginServiceChild> service =
+      GeckoMediaPluginServiceChild::GetSingleton();
+  MOZ_ASSERT(service && service->mServiceChild.get() == this);
+  if (service) {
+    service->BeginShutdown();
+  }
+  return IPC_OK();
+}
+
+bool GMPServiceChild::HaveContentParents() const {
+  return mContentParents.Count() > 0;
+}
+
+}  // namespace mozilla::gmp
+
+#undef __CLASS__