FYI https://issues.apache.org/jira/browse/CB-2621
The bridge works but it has no plugins to call yet. The bridge is by binding an object at window.cordovabridge which has a native exec function. My initial idea is to keep using the opaque callbackId reference like iOS for possible plugin re-use. We don't have to do that of course, since we can keep a JavaScriptCore C API reference to the actual JavaScript callbacks and call them directly, not sure of adding this added complexity for plugin authors (we can have wrappers of course).