Index: lib/asan/scripts/asan_symbolize.py
===================================================================
--- lib/asan/scripts/asan_symbolize.py
+++ lib/asan/scripts/asan_symbolize.py
@@ -11,11 +11,9 @@
 import bisect
 import getopt
 import os
-import pty
 import re
 import subprocess
 import sys
-import termios
 
 symbolizers = {}
 DEBUG = False
@@ -171,6 +169,9 @@
   output.  Uses pty to trick the child into providing unbuffered output.
   """
   def __init__(self, args, close_stderr=False):
+    # Local imports so that the script can start on Windows.
+    import pty
+    import termios
     pid, fd = pty.fork()
     if pid == 0:
       # We're the child. Transfer control to command.
@@ -405,10 +406,7 @@
 
   def process_logfile(self):
     self.frame_no = 0
-    while True:
-      line = logfile.readline()
-      if not line:
-        break
+    for line in logfile:
       processed = self.process_line(line)
       print '\n'.join(processed)
 
@@ -437,20 +435,23 @@
 
 
 if __name__ == '__main__':
-  parser = argparse.ArgumentParser(formatter_class=argparse.RawDescriptionHelpFormatter,
-  description='ASan symbolization script',
-  epilog='''Example of use:
-  asan_symbolize.py -c "$HOME/opt/cross/bin/arm-linux-gnueabi-" -s "$HOME/SymbolFiles" < asan.log''')
+  parser = argparse.ArgumentParser(
+      formatter_class=argparse.RawDescriptionHelpFormatter,
+      description='ASan symbolization script',
+      epilog='Example of use:\n'
+             'asan_symbolize.py -c "$HOME/opt/cross/bin/arm-linux-gnueabi-" '
+             '-s "$HOME/SymbolFiles" < asan.log')
   parser.add_argument('path_to_cut', nargs='*',
-    help='pattern to be cut from the result file path ')
+                      help='pattern to be cut from the result file path ')
   parser.add_argument('-d','--demangle', action='store_true',
-    help='demangle function names')
+                      help='demangle function names')
   parser.add_argument('-s', metavar='SYSROOT',
-    help='set path to sysroot for sanitized binaries')
+                      help='set path to sysroot for sanitized binaries')
   parser.add_argument('-c', metavar='CROSS_COMPILE',
-    help='set prefix for binutils')
-  parser.add_argument('-l','--logfile', default=sys.stdin, type=argparse.FileType('r'),
-    help='set log file name to parse, default is stdin')
+                      help='set prefix for binutils')
+  parser.add_argument('-l','--logfile', default=sys.stdin,
+                      type=argparse.FileType('r'),
+                      help='set log file name to parse, default is stdin')
   args = parser.parse_args()
   if args.path_to_cut:
     fix_filename_patterns = args.path_to_cut
@@ -465,5 +466,13 @@
     logfile = args.logfile
   else:
     logfile = sys.stdin
+
+  if sys.platform == 'win32':
+    # ASan on Windows uses dbghelp.dll to symbolize in-process, which works even
+    # in sandboxed processes.  This script isn't needed there.
+    for line in logfile:
+      print line,
+    sys.exit(0)
+
   loop = SymbolizationLoop(binary_name_filter)
   loop.process_logfile()