Bug 1451913 P10 Make the inner window explicitly disconnect the IDBFactory. r=baku

dom/base/nsGlobalWindowInner.cpp

@@ -1230,7 +1230,10 @@ nsGlobalWindowInner::FreeInnerObjects()
     mApplicationCache = nullptr;
   }
 
-  mIndexedDB = nullptr;
+  if (mIndexedDB) {
+    mIndexedDB->DisconnectFromWindow(this);
+    mIndexedDB = nullptr;
+  }
 
   UnlinkHostObjectURIs();
 
@@ -1524,7 +1527,10 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsGlobalWindowInner)
     static_cast<nsDOMOfflineResourceList*>(tmp->mApplicationCache.get())->Disconnect();
     NS_IMPL_CYCLE_COLLECTION_UNLINK(mApplicationCache)
   }
-  NS_IMPL_CYCLE_COLLECTION_UNLINK(mIndexedDB)
+  if (tmp->mIndexedDB) {
+    tmp->mIndexedDB->DisconnectFromWindow(tmp);
+    NS_IMPL_CYCLE_COLLECTION_UNLINK(mIndexedDB)
+  }
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mDocumentPrincipal)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mTabChild)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mDoc)

dom/indexedDB/IDBFactory.cpp

@@ -895,6 +895,16 @@ IDBFactory::RebindToNewWindow(nsPIDOMWindowInner* aNewWindow)
   mWindow->UpdateActiveIndexedDBDatabaseCount(mActiveDatabaseCount);
 }
 
+void
+IDBFactory::DisconnectFromWindow(nsPIDOMWindowInner* aOldWindow)
+{
+  MOZ_DIAGNOSTIC_ASSERT(aOldWindow);
+  // If CC unlinks us first, then mWindow might be nullptr
+  MOZ_DIAGNOSTIC_ASSERT(!mWindow || mWindow == aOldWindow);
+
+  mWindow = nullptr;
+}
+
 NS_IMPL_CYCLE_COLLECTING_ADDREF(IDBFactory)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(IDBFactory)
 

dom/indexedDB/IDBFactory.h

@@ -230,6 +230,9 @@ public:
   void
   RebindToNewWindow(nsPIDOMWindowInner* aNewWindow);
 
+  void
+  DisconnectFromWindow(nsPIDOMWindowInner* aOldWindow);
+
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(IDBFactory)