Move more of android file handling in Java

Moving some of the code (finding which kind of file it is and
deleting parts of the url) to Java from C++.

Is needed by the following change in external/webkit:
https://android-git.corp.google.com/g/#change,77383

Change-Id: Ifc6008501eb580a0aaa5e307732b6f49ebd19ac4
1 file changed