onPostMessage method
Called when a tab controlled by this PlatformChromeSafariBrowser has sent a postMessage. If PlatformChromeSafariBrowser.postMessage is called from a single thread, then the messages will be posted in the same order. When received on the client side, it is the client's responsibility to preserve the ordering further.
Officially Supported Platforms/Implementations:
Implementation
@override
void onPostMessage(String message) {}