Bug 1769155 - Null-check win in setter for IsActiveBrowserWindowInternal. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D148914

docshell/base/BrowsingContext.cpp

@@ -2998,19 +2998,21 @@ void BrowsingContext::DidSet(FieldIndex<IDX_IsActiveBrowserWindowInternal>,
       doc->UpdateDocumentStates(DocumentState::WINDOW_INACTIVE, true);
 
       RefPtr<nsPIDOMWindowInner> win = doc->GetInnerWindow();
-      RefPtr<MediaDevices> devices;
-      if (isActivateEvent && (devices = win->GetExtantMediaDevices())) {
-        devices->BrowserWindowBecameActive();
-      }
+      if (win) {
+        RefPtr<MediaDevices> devices;
+        if (isActivateEvent && (devices = win->GetExtantMediaDevices())) {
+          devices->BrowserWindowBecameActive();
+        }
 
-      if (XRE_IsContentProcess() &&
-          (!aContext->GetParent() || !aContext->GetParent()->IsInProcess())) {
-        // Send the inner window an activate/deactivate event if
-        // the context is the top of a sub-tree of in-process
-        // contexts.
-        nsContentUtils::DispatchEventOnlyToChrome(
-            doc, win, isActivateEvent ? u"activate"_ns : u"deactivate"_ns,
-            CanBubble::eYes, Cancelable::eYes, nullptr);
+        if (XRE_IsContentProcess() &&
+            (!aContext->GetParent() || !aContext->GetParent()->IsInProcess())) {
+          // Send the inner window an activate/deactivate event if
+          // the context is the top of a sub-tree of in-process
+          // contexts.
+          nsContentUtils::DispatchEventOnlyToChrome(
+              doc, win, isActivateEvent ? u"activate"_ns : u"deactivate"_ns,
+              CanBubble::eYes, Cancelable::eYes, nullptr);
+        }
       }
     }
   });