By searching google for code snippets do force an update to the app cache of my Web View I did not found any good method to do it, so here is my recipe to force an update to the app cache.
1) before load url disable the cache
2) when the browser is ready, and resources are downloaded ( from the new version of the manifest)
3) load again the url, and you have the new version of app cache.
That it. A Three phase method, just like a normal browser do.
Oscar Brito - http:://divhide.com