Bug 1675820 - Part 2: Trace inner window mBrowsingContext and mWindowGlobalChild fields, r=smaug

When these fields were added, it appears I completely forgot to add them to the
cycle collection unlink logic. This somehow didn't cause leaks due to existing
code which would break the cycles between the inner window and the outer window
/ BrowsingContext.

Differential Revision: https://phabricator.services.mozilla.com/D108118

dom/base/nsGlobalWindowInner.cpp

@@ -1451,6 +1451,8 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(nsGlobalWindowInner)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mChromeEventHandler)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParentTarget)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFocusedElement)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mBrowsingContext)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mWindowGlobalChild)
 
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMenubar)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mToolbar)
@@ -1552,6 +1554,12 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsGlobalWindowInner)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mChromeEventHandler)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mParentTarget)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mFocusedElement)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mBrowsingContext)
+
+  MOZ_DIAGNOSTIC_ASSERT(
+      !tmp->mWindowGlobalChild || tmp->mWindowGlobalChild->IsClosed(),
+      "How are we unlinking a window before its actor has been destroyed?");
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mWindowGlobalChild)
 
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mMenubar)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mToolbar)
@@ -2745,16 +2753,13 @@ bool nsPIDOMWindowInner::HasOpenWebSockets() const {
 }
 
 bool nsPIDOMWindowInner::IsCurrentInnerWindow() const {
-  auto* bc = GetBrowsingContext();
-  MOZ_ASSERT(bc);
-
-  if (bc->IsDiscarded()) {
+  if (!mBrowsingContext || mBrowsingContext->IsDiscarded()) {
     // If our BrowsingContext has been discarded, we consider ourselves
     // still-current if we were current at the time it was discarded.
     return mOuterWindow && WasCurrentInnerWindow();
   }
 
-  nsPIDOMWindowOuter* outer = bc->GetDOMWindow();
+  nsPIDOMWindowOuter* outer = mBrowsingContext->GetDOMWindow();
   return outer && outer->GetCurrentInnerWindow() == this;
 }