perf hists browser: Allow annotating entries in callchains

Instead of annotating just the top level hist_entry, allow instead
annotating a map_symbol, i.e. the top level hist_entry or one of the
callchains for which there were samples.

Suggested-by: Stephane Eranian <eranian@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-k1zxj5564je9jei4yd15ouwn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index e988c9f..9f31b89 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -303,6 +303,9 @@
 
 #ifdef HAVE_SLANG_SUPPORT
 #include "../ui/keysyms.h"
+int map_symbol__tui_annotate(struct map_symbol *ms, struct perf_evsel *evsel,
+			     struct hist_browser_timer *hbt);
+
 int hist_entry__tui_annotate(struct hist_entry *he, struct perf_evsel *evsel,
 			     struct hist_browser_timer *hbt);
 
@@ -321,6 +324,12 @@
 {
 	return 0;
 }
+static inline int map_symbol__tui_annotate(struct map_symbol *ms __maybe_unused,
+					   struct perf_evsel *evsel __maybe_unused,
+					   struct hist_browser_timer *hbt __maybe_unused)
+{
+	return 0;
+}
 
 static inline int hist_entry__tui_annotate(struct hist_entry *he __maybe_unused,
 					   struct perf_evsel *evsel __maybe_unused,