predictors: Move the configuration of speculative prefetch to field trials.

tools/android/customtabs_benchmark/scripts/customtabs_benchmark.py

 #!/usr/bin/python
 #
 # Copyright 2015 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.
 
 """Loops Custom Tabs tests and outputs the results into a CSV file."""
 
 import collections
 import contextlib
@@ skipping 169 matching lines @@
     try:
       while should_stop is None or not should_stop.is_set():
         config = configs[random.randint(0, len(configs) - 1)]
         chrome_args = CHROME_ARGS + wpr_attributes.chrome_args
         if config['speculation_mode'] == 'no_state_prefetch':
           # NoStatePrefetch is enabled through an experiment.
           chrome_args.extend([
               '--force-fieldtrials=trial/group',
               '--force-fieldtrial-params=trial.group:mode/no_state_prefetch',
               '--enable-features="NoStatePrefetch<trial"'])
+        elif config['speculation_mode'] == 'speculative_prefetch':
+          # Speculative Prefetch is enabled through an experiment.
+          chrome_args.extend([
+              '--force-fieldtrials=trial/group',
+              '--force-fieldtrial-params=trial.group:mode/external-prefetching',
+              '--enable-features="SpeculativeResourcePrefetching<trial"'])
 
         result = RunOnce(device, config['url'], config['warmup'],
                          config['speculation_mode'],
                          config['delay_to_may_launch_url'],
                          config['delay_to_launch_url'], config['cold'],
                          chrome_args, reset_chrome_state=True)
         if result is not None:
           out.write(result + '\n')
           out.flush()
         if once:
@@ skipping 117 matching lines @@
       'delay_to_launch_url': options.delay_to_launch_url,
       'cold': options.cold,
   }
   LoopOnDevice(device, [config], options.output_file, options.wpr_archive,
                options.record, options.network_condition, options.wpr_log,
                once=options.once)
 
 
 if __name__ == '__main__':
   main()