Use BaseService for thrift-handler from oss-fb303

Summary:
This diff adds fb303 dependency to Open/R. fb303 is FB's open-sourced project
which provides basic infrastructure for thrift service e.g. base functions,
counters supports etc.

Using this in Open/R will allow both internal & external users leverage counters
via thrift APIs

Reviewed By: xiangxu1121

Differential Revision: D20134243

fbshipit-source-id: 23782ec99dc749dd27dc19f2b2b023f1c229608b

build/fbcode_builder/manifests/openr

@@ -17,6 +17,7 @@ builder = nop
 
 [dependencies]
 boost
+fb303
 fbthrift
 fbzmq
 folly