Cleanup potential mouse forwarding resources when window is destroyed.

atom/browser/native_window_views.cc

@@ -334,6 +334,11 @@ NativeWindowViews::NativeWindowViews(
 
 NativeWindowViews::~NativeWindowViews() {
   window_->RemoveObserver(this);
+
+#if defined(OS_WIN)
+  // Disable mouse forwarding to relinquish resources, should any be held.
+  SetForwardMouseMessages(false);
+#endif
 }
 
 void NativeWindowViews::Close() {