perf session: Adopt resolve_callchain

This is really a generic library routine, so declutter
builtin-report.c a bit by moving it to the library.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1260807780-19377-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 759d960..a8f3a49 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -6,7 +6,9 @@
 #include "thread.h"
 #include <linux/rbtree.h>
 
+struct ip_callchain;
 struct thread;
+struct symbol;
 struct symbol_conf;
 
 struct perf_session {
@@ -50,6 +52,11 @@
 int perf_session__process_events(struct perf_session *self,
 				 struct perf_event_ops *event_ops);
 
+struct symbol **perf_session__resolve_callchain(struct perf_session *self,
+						struct thread *thread,
+						struct ip_callchain *chain,
+						struct symbol **parent);
+
 int perf_header__read_build_ids(int input, u64 offset, u64 file_size);
 
 #endif /* __PERF_SESSION_H */