Fix bisect-builds.py crash for non-official win64 builds

tools/bisect-builds.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """Snapshot Build Bisect Tool
 
 This script bisects a snapshot archive using binary search. It starts at
 a bad revision (it will try to guess HEAD) and asks for a last known-good
 revision. It will then binary search across this revision range by downloading,
@@ skipping 139 matching lines @@
         self._listing_platform_dir = 'Linux_x64/'
       elif self.platform == 'linux-arm':
         self._listing_platform_dir = 'Linux_ARM_Cross-Compile/'
       elif self.platform == 'chromeos':
         self._listing_platform_dir = 'Linux_ChromiumOS_Full/'
     elif self.platform in ('mac', 'mac64'):
       self._listing_platform_dir = 'Mac/'
       self._binary_name = 'Chromium.app/Contents/MacOS/Chromium'
     elif self.platform == 'win':
       self._listing_platform_dir = 'Win/'
+    elif self.platform == 'win64':
+      self._listing_platform_dir = 'Win_x64/'
 
   def GetASANPlatformDir(self):
     """ASAN builds are in directories like "linux-release", or have filenames
     like "asan-win32-release-277079.zip". This aligns to our platform names
     except in the case of Windows where they use "win32" instead of "win"."""
     if self.platform == 'win':
       return 'win32'
     else:
       return self.platform
 
@@ skipping 993 matching lines @@
     if min_blink_rev != max_blink_rev:
       print ('NOTE: There is a Blink roll in the range, '
              'you might also want to do a Blink bisect.')
 
     print 'CHANGELOG URL:'
     PrintChangeLog(min_chromium_rev, max_chromium_rev)
 
 
 if __name__ == '__main__':
   sys.exit(main())