sandwich: Fix some trivial failures on SWR benchmark runs

tools/android/loading/request_track.py

 # Copyright (c) 2016 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.
 
 """The request data track.
 
 When executed, parses a JSON dump of DevTools messages.
 """
 
 import bisect
@@ skipping 323 matching lines @@
     return self.status is not None
 
   def GetCacheControlDirective(self, directive_name):
     """Returns the value of a Cache-Control directive, or None."""
     cache_control_str = self.GetHTTPResponseHeader('Cache-Control')
     if cache_control_str is None:
       return None
     directives = [s.strip() for s in cache_control_str.split(',')]
     for directive in directives:
       parts = directive.split('=')
-      if len(parts) == 1:
+      if len(parts) != 2:

[pasko, 2016/07/11 11:26:50]

was it an empty directive or more than one '='? Is it because of typos on the
web devs side or something legitimate?

[gabadie, 2016/07/11 12:14:35]

I had a Cache-Control: max-age=stuff1 max-age=stuff2 with the missing `,` in
between, making len(parts) == 3

         continue
       (name, value) = parts
       if name == directive_name:
         return value
     return None
 
   def MaxAge(self):
     """Returns the max-age of a resource, or -1."""
     # TODO(lizeb): Handle the "Expires" header as well.
     cache_control = {}
@@ skipping 23 matching lines @@
     request_time and the latest timing event.
     """
     # All fields in timing are millis relative to request_time.
     return self.timing.LargestOffset()
 
   def GetRawResponseHeaders(self):
     """Gets the request's raw response headers compatible with
     net::HttpResponseHeaders's constructor.
     """
     assert not self.IsDataRequest()
+    assert self.HasReceivedResponse()
     headers = '{} {} {}\x00'.format(
         self.protocol.upper(), self.status, self.status_text)
     for key in sorted(self.response_headers.keys()):
-      headers += '{}: {}\x00'.format(key, self.response_headers[key])
+      try:
+        headers += '{}: {}\x00'.format(

[pasko, 2016/07/11 11:26:50]

response headers do not have to be valid unicode, trying to decode/encode it,
then setting headers with errors ignored .. look wrong.

can we 'just' concatenate two byte sequences here that read before?

[gabadie, 2016/07/11 12:14:35]

Good point. Done.

+            str(key), str(self.response_headers[key]))
+      except UnicodeEncodeError:
+        logging.exception('failure when encoding one of the following: %s, %s',
+            repr(key), repr(self.response_headers[key]))
     return headers
 
   def __eq__(self, o):
     return self.__dict__ == o.__dict__
 
   def __hash__(self):
     return hash(self.request_id)
 
   def __str__(self):
     return json.dumps(self.ToJsonDict(), sort_keys=True, indent=2)
@@ skipping 460 matching lines @@
 
 
 if __name__ == '__main__':
   import json
   import sys
   events = json.load(open(sys.argv[1], 'r'))
   request_track = RequestTrack(None)
   for event in events:
     event_method = event['method']
     request_track.Handle(event_method, event)