Bug 1216972 - MediaManager AsyncShutdown for content processes. r=jesup

--HG--
extra : transplant_source : %D9%A4%C4%95%EB%F9%0Fh%83z%21%91A5cu7%B4%DF%DE

dom/media/MediaManager.cpp

@@ -98,6 +98,23 @@ struct nsIMediaDevice::COMTypeInfo<mozilla::AudioDevice, void> {
 };
 const nsIID nsIMediaDevice::COMTypeInfo<mozilla::AudioDevice, void>::kIID = NS_IMEDIADEVICE_IID;
 
+namespace {
+already_AddRefed<nsIAsyncShutdownClient> GetShutdownPhase() {
+  nsCOMPtr<nsIAsyncShutdownService> svc = services::GetAsyncShutdown();
+  MOZ_RELEASE_ASSERT(svc);
+
+  nsCOMPtr<nsIAsyncShutdownClient> shutdownPhase;
+  nsresult rv = svc->GetProfileBeforeChange(getter_AddRefs(shutdownPhase));
+  if (!shutdownPhase) {
+    // We are probably in a content process.
+    rv = svc->GetContentChildShutdown(getter_AddRefs(shutdownPhase));
+  }
+  MOZ_RELEASE_ASSERT(shutdownPhase);
+  MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+  return shutdownPhase.forget();
+}
+}
+
 namespace mozilla {
 
 #ifdef LOG
@@ -1560,13 +1577,7 @@ MediaManager::Get() {
 
     // Prepare async shutdown
 
-    nsCOMPtr<nsIAsyncShutdownClient> profileBeforeChange;
-    {
-      nsCOMPtr<nsIAsyncShutdownService> svc = services::GetAsyncShutdown();
-      MOZ_RELEASE_ASSERT(svc);
-      nsresult rv = svc->GetProfileBeforeChange(getter_AddRefs(profileBeforeChange));
-      MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
-    }
+    nsCOMPtr<nsIAsyncShutdownClient> shutdownPhase = GetShutdownPhase();
 
     class Blocker : public media::ShutdownBlocker
     {
@@ -1575,7 +1586,7 @@ MediaManager::Get() {
       : media::ShutdownBlocker(NS_LITERAL_STRING(
           "Media shutdown: blocking on media thread")) {}
 
-      NS_IMETHOD BlockShutdown(nsIAsyncShutdownClient* aProfileBeforeChange) override
+      NS_IMETHOD BlockShutdown(nsIAsyncShutdownClient*) override
       {
         MOZ_RELEASE_ASSERT(MediaManager::GetIfExists());
         MediaManager::GetIfExists()->Shutdown();
@@ -1584,10 +1595,10 @@ MediaManager::Get() {
     };
 
     sSingleton->mShutdownBlocker = new Blocker();
-    nsresult rv = profileBeforeChange->AddBlocker(sSingleton->mShutdownBlocker,
-                                                  NS_LITERAL_STRING(__FILE__),
-                                                  __LINE__,
-                                                  NS_LITERAL_STRING("Media shutdown"));
+    nsresult rv = shutdownPhase->AddBlocker(sSingleton->mShutdownBlocker,
+                                            NS_LITERAL_STRING(__FILE__),
+                                            __LINE__,
+                                            NS_LITERAL_STRING("Media shutdown"));
     MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
 #ifdef MOZ_B2G
     // Init MediaPermissionManager before sending out any permission requests.
@@ -2654,14 +2665,8 @@ MediaManager::Shutdown()
 
     // Remove async shutdown blocker
 
-    nsCOMPtr<nsIAsyncShutdownClient> profileBeforeChange;
-    {
-      nsCOMPtr<nsIAsyncShutdownService> svc = services::GetAsyncShutdown();
-      MOZ_RELEASE_ASSERT(svc);
-      nsresult rv = svc->GetProfileBeforeChange(getter_AddRefs(profileBeforeChange));
-      MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
-    }
-    profileBeforeChange->RemoveBlocker(sSingleton->mShutdownBlocker);
+    nsCOMPtr<nsIAsyncShutdownClient> shutdownPhase = GetShutdownPhase();
+    shutdownPhase->RemoveBlocker(sSingleton->mShutdownBlocker);
 
     // we hold a ref to 'that' which is the same as sSingleton
     sSingleton = nullptr;