Bug 1325255 - Don't crash during shutdown if the deserialization of the principal fails; r=bkelly

dom/ipc/ContentParent.cpp

@@ -4800,7 +4800,8 @@ ContentParent::RecvPURLClassifierConstructor(PURLClassifierParent* aActor,
   auto* actor = static_cast<URLClassifierParent*>(aActor);
   nsCOMPtr<nsIPrincipal> principal(aPrincipal);
   if (!principal) {
-    return IPC_FAIL_NO_REASON(this);
+    actor->ClassificationFailed();
+    return IPC_OK();
   }
   return actor->StartClassify(principal, aUseTrackingProtection, aSuccess);
 }

dom/ipc/URLClassifierParent.cpp

@@ -34,7 +34,7 @@ URLClassifierParent::StartClassify(nsIPrincipal* aPrincipal,
     // without ever calling out callback in both cases.
     // This means that code using this in the child process will only get a hit
     // on its callback if some classification actually happens.
-    Unused << Send__delete__(this, void_t());
+    ClassificationFailed();
   }
   return IPC_OK();
 }
@@ -48,6 +48,14 @@ URLClassifierParent::OnClassifyComplete(nsresult aRv)
   return NS_OK;
 }
 
+void
+URLClassifierParent::ClassificationFailed()
+{
+  if (mIPCOpen) {
+    Unused << Send__delete__(this, void_t());
+  }
+}
+
 void
 URLClassifierParent::ActorDestroy(ActorDestroyReason aWhy)
 {

dom/ipc/URLClassifierParent.h

@@ -27,6 +27,8 @@ class URLClassifierParent : public nsIURIClassifierCallback,
                                         bool* aSuccess);
   void ActorDestroy(ActorDestroyReason aWhy) override;
 
+  void ClassificationFailed();
+
  private:
   ~URLClassifierParent() = default;