Merge flush code phase into marking phase.

tools/gc-nvp-trace-processor.py

 #!/usr/bin/env python
 #
 # Copyright 2010 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 270 matching lines @@
   marksweeps = filter(lambda r: r['gc'] == 'ms', trace)
   markcompacts = filter(lambda r: r['gc'] == 'mc', trace)
   scavenges = filter(lambda r: r['gc'] == 's', trace)
 
   charts = plot_all(plots, trace, filename)
 
   def stats(out, prefix, trace, field):
     n = len(trace)
     total = calc_total(trace, field)
     max = calc_max(trace, field)
-    avg = total / n
+    if n > 0:
+      avg = total / n
+    else:
+      avg = 0
     if n > 1:
       dev = math.sqrt(freduce(lambda t,r: (r - avg) ** 2, field, trace, 0) /
                       (n - 1))
     else:
       dev = 0
 
     out.write('<tr><td>%s</td><td>%d</td><td>%d</td>'
               '<td>%d</td><td>%d [dev %f]</td></tr>' %
               (prefix, n, total, max, avg, dev))
 
@@ skipping 15 matching lines @@
       out.write('<img src="%s">' % chart)
       out.write('</body></html>')
 
   print "%s generated." % (filename + '.html')
 
 if len(sys.argv) != 2:
   print "Usage: %s <GC-trace-filename>" % sys.argv[0]
   sys.exit(1)
 
 process_trace(sys.argv[1])