Version: ToT
OS: Android

Currently GetMedata() returns |ListValue| with |DictionaryValue|s inside.
This may be inconvenient:

1) There is no static check that you provide to your clients what they expect;

2) You can easily break someone, such that it is visible to the users;

3) Clients have to do a lot of |DCHECKS|s;

4) In order to understand what is returned, one needs to go a long way up to Java code. 

Have you considered returning a vector of structs instead?