Add one row Total_events_of_this_profile in perf report.

BUG=None
TEST=It shows the number in the report.

Change-Id: I5f28346552b9a96f8d3475880258618dc8e0a99a
Reviewed-on: https://gerrit-int.chromium.org/33974
Reviewed-by: Luis Lozano <llozano@chromium.org>
Commit-Queue: Yunlian Jiang <yunlian@google.com>
Tested-by: Yunlian Jiang <yunlian@google.com>
diff --git a/utils/perf_diff.py b/utils/perf_diff.py
index d56eba1..47cb1ef 100755
--- a/utils/perf_diff.py
+++ b/utils/perf_diff.py
@@ -16,6 +16,8 @@
 import tabulator
 
 ROWS_TO_SHOW = "Rows_to_show_in_the_perf_table"
+TOTAL_EVENTS = "Total_events_of_this_profile"
+
 
 def GetPerfDictFromReport(report_file):
   output = {}
@@ -24,9 +26,11 @@
     if k not in output:
       output[k] = {}
     output[k][ROWS_TO_SHOW] = 0
+    output[k][TOTAL_EVENTS] = 0
     for function in v.functions:
       out_key = "%s" % (function.name)
       output[k][out_key] = function.count
+      output[k][TOTAL_EVENTS] += function.count
       if function.percent > 1:
         output[k][ROWS_TO_SHOW] += 1
   return output