perf browsers: Add live mode to the hists, annotate browsers

This allows passing a timer to be run periodically, which will update
the hists tree that then gers refreshed on the screen, just like the
Live mode (symbol entries, annotation) we already have in 'perf top
--tui'.

Will be used by the new hist_entry/hists based 'top' tool.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-2r44qd8oe4sagzcgoikl8qzc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index f349150..6be71fc 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -25,6 +25,7 @@
 	struct pollfd	 *pollfd;
 	struct thread_map *threads;
 	struct cpu_map	  *cpus;
+	struct perf_evsel *selected;
 };
 
 struct perf_evsel;
@@ -56,6 +57,9 @@
 void perf_evlist__disable(struct perf_evlist *evlist);
 void perf_evlist__enable(struct perf_evlist *evlist);
 
+void perf_evlist__set_selected(struct perf_evlist *evlist,
+			       struct perf_evsel *evsel);
+
 static inline void perf_evlist__set_maps(struct perf_evlist *evlist,
 					 struct cpu_map *cpus,
 					 struct thread_map *threads)