styling tipps and other stuff

added some comments how you could improve some aspects.
Main aspects are:
* naming conventions
* extract every class to its own file (distinquish with packages between 'big subjects' not class files)
* also split up not-reused methods into their own methods, so that everyone can understand your code and probably use it too.
-- do this for small tasks especially, you will also find some cases where you can reuse created methods.
* for e.g. preference -tags (or names, ids, however you call it) use constants. E.g. create a .java file called BrowserPreferences
-- create public static final String variables with meaning full names (and following the naming conventions) for each constant.. 
-----e.g. public static final String PREF_USER_AGENT = "useragent";
----- or.. public static final String PREF_SOMETHING_ELSE = "somethingelse";
--- and access them via Classname.CONSTANT_NAME .. e.g. BrowserPreferences.PREF_USER_AGENT this is especially useful for avoiding errors when reusing them. (like typos) and you can easily change them afterwards.
*don't use getters too much if you need objects more than once.
-- e.g. instead use: MyObject obj = someObject.getMyObject(); 
--                   obj.setSomething("BLA!"); obj.setSomethingElse(true);

and much more stuff, but I hope these tipps might increase the style of your code a bit. :)