perf script: Add process_stat/process_stat_interval scripting interface

Python and perl scripting code will define those callbacks and get stat
data.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Kan Liang <kan.liang@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1452028152-26762-5-git-send-email-jolsa@kernel.org
[ Rename 'time' parameters to 'tstamp', to fix the build in older distros ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/trace-event.h

@@ -65,6 +65,7 @@ int tracing_data_put(struct tracing_data *tdata);
 struct addr_location;
 
 struct perf_session;
+struct perf_stat_config;
 
 struct scripting_ops {
 	const char *name;
@@ -75,6 +76,9 @@ struct scripting_ops {
 			       struct perf_sample *sample,
 			       struct perf_evsel *evsel,
 			       struct addr_location *al);
+	void (*process_stat)(struct perf_stat_config *config,
+			     struct perf_evsel *evsel, u64 tstamp);
+	void (*process_stat_interval)(u64 tstamp);
 	int (*generate_script) (struct pevent *pevent, const char *outfile);
 };