Bug 1587366 - Fix VRManagerParent::GetVRActiveStatus race condition: Notify VRActiveStatus after a the VREventObserver is created. r=rbarker,daoshengmu

Notify VRActiveStatus after a the VREventObserver is created to prevent the VRManagerParent::GetVRActiveStatus race condition.
Call VRManager::Shutdown() when the app goes to background instead of calling it in the foreground event due to the inactivity timer.

Differential Revision: https://phabricator.services.mozilla.com/D48678

--HG--
extra : moz-landing-system : lando

dom/base/nsGlobalWindowInner.cpp

@@ -4070,6 +4070,10 @@ void nsGlobalWindowInner::DisableGamepadUpdates() {
 void nsGlobalWindowInner::EnableVRUpdates() {
   if (mHasVREvents && !mVREventObserver) {
     mVREventObserver = new VREventObserver(this);
+    nsPIDOMWindowOuter* outer = GetOuterWindow();
+    if (outer && !outer->IsBackground()) {
+      mVREventObserver->StartActivity();
+    }
   }
 }
 

gfx/vr/VRManager.cpp

@@ -305,8 +305,9 @@ void VRManager::TaskTimerCallback(nsITimer* aTimer, void* aClosure) {
 
   if (self->mAppPaused) {
     // When the apps goes the background (e.g. Android) we should stop the
-    // tasks.
+    // tasks and shutdown.
     self->StopTasks();
+    self->Shutdown();
   }
 }