Update from https://crrev.com/314320

tools/valgrind/memcheck_analyze.py

 #!/usr/bin/env python
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # memcheck_analyze.py
 
 ''' Given a valgrind XML file, parses errors and uniques them.'''
 
 import gdb_helper
@@ skipping 213 matching lines @@
         self._additional.append(description)
         description = None
 
       if node.localName == "suppression":
         self._suppression = getCDATAOf(node, "rawtext");
 
   def __str__(self):
     ''' Pretty print the type and backtrace(s) of this specific error,
         including suppression (which is just a mangled backtrace).'''
     output = ""
+    output += "\n" # Make sure the ### is at the beginning of line.
+    output += "### BEGIN MEMORY TOOL REPORT (error hash=#%016X#)\n" % \
+        self.ErrorHash()
     if (self._commandline):
       output += self._commandline + "\n"
 
     output += self._kind + "\n"
     for backtrace in self._backtraces:
       output += backtrace[0] + "\n"
       filter = subprocess.Popen("c++filt -n", stdin=subprocess.PIPE,
                                 stdout=subprocess.PIPE,
                                 stderr=subprocess.STDOUT,
                                 shell=True,
@@ skipping 76 matching lines @@
 
     for frame in range(len(supplines)):
       # Replace the always-changing anonymous namespace prefix with "*".
       m = re.match("( +fun:)_ZN.*_GLOBAL__N_.*\.cc_" +
                    "[0-9a-fA-F]{8}_[0-9a-fA-F]{8}(.*)",
                    supplines[frame])
       if m:
         supplines[frame] = "*".join(m.groups())
 
     output += "\n".join(supplines) + "\n"
+    output += "### END MEMORY TOOL REPORT (error hash=#%016X#)\n" % \
+        self.ErrorHash()
 
     return output
 
   def UniqueString(self):
     ''' String to use for object identity. Don't print this, use str(obj)
     instead.'''
     rep = self._kind + " "
     for backtrace in self._backtraces:
       for frame in backtrace[1]:
         rep += frame[FUNCTION_NAME]
@@ skipping 286 matching lines @@
   if len(args) == 0:
     parser.error("no filename specified")
   filenames = args
 
   analyzer = MemcheckAnalyzer(options.source_dir, use_gdb=True)
   return analyzer.Report(filenames, None)
 
 
 if __name__ == "__main__":
   sys.exit(_main())