Teach mojo_benchmark --save-traces to pull results from Android devices.

mojo/devtools/common/mojo_benchmark

 #!/usr/bin/env 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.
 
 """Runner for Mojo application benchmarks."""
 
 import argparse
 import logging
 import sys
 import time
+import os.path
 
 from devtoolslib import shell_arguments
 from devtoolslib import shell_config
 
 
 _DESCRIPTION = """Runner for Mojo application benchmarks.
 
 |benchmark_list_file| has to be a valid Python program that sets a |benchmarks|
 global variable, containing entries of the following form:
 
@@ skipping 24 matching lines @@
 _BENCHMARK_APP = 'https://core.mojoapps.io/benchmark.mojo'
 _CACHE_SERVICE_URL = 'mojo:url_response_disk_cache'
 _NETWORK_SERVICE_URL = 'mojo:network_service'
 
 # Additional time in seconds allocated per shell run to accommodate start-up.
 # The shell should terminate before hitting this time out, it is an error if it
 # doesn't.
 _EXTRA_TIMEOUT = 20
 
 
+def _get_output_file(shell, name, cold_start):
+    file_name = 'benchmark-%s-%s-%s.trace' % (
+        name.replace(' ', '_'),
+        'cold_start' if cold_start else 'warm_start',
+        time.strftime('%Y%m%d%H%M%S'))
+    return file_name
+
+
 def _run_benchmark(shell, shell_args, name, app, duration_seconds, measurements,
-                   cold_start, verbose, save_traces):
+                   cold_start, verbose, android, save_traces):
   """Runs `benchmark.mojo` in shell with correct arguments, parses and
   presents the benchmark results.
   """
   timeout = duration_seconds + _EXTRA_TIMEOUT
   benchmark_args = []
   benchmark_args.append('--app=' + app)
   benchmark_args.append('--duration=' + str(duration_seconds))
+
+  output_file = None
+  device_output_file = None
   if save_traces:
-    trace_output_file = 'benchmark-%s-%s-%s.trace' % (
-        name.replace(' ', '_'),
-        'cold_start' if cold_start else 'warm_start',
-        time.strftime('%Y%m%d%H%M%S'))
-    benchmark_args.append('--trace-output=' + trace_output_file)
+    output_file = _get_output_file(shell, name, cold_start)
+    if android:
+      device_output_file = os.path.join(shell.get_tmp_dir_path(), output_file)
+      benchmark_args.append('--trace-output=' + device_output_file)
+    else:
+      benchmark_args.append('--trace-output=' + output_file)
 
   for measurement in measurements:
     benchmark_args.append(measurement)
 
   shell_args = list(shell_args)
   shell_args.append(_BENCHMARK_APP)
   shell_args.append('--force-offline-by-default')
   shell_args.append('--args-for=%s %s' % (_BENCHMARK_APP,
                                           ' '.join(benchmark_args)))
 
@@ skipping 14 matching lines @@
       print 'Return code: ' + str(return_code)
     print 'Output: '
     print output
     print '-' * 72
     return False
 
   # Echo measurement results.
   for line in output_lines:
     if line.strip().startswith('measurement:') or 'WARNING' in line:
       print line
+
+  if device_output_file:
+    shell.pull_file(device_output_file, output_file, remove_original=True)
   return True
 
 
 def main():
   parser = argparse.ArgumentParser(
       formatter_class=argparse.RawDescriptionHelpFormatter,
       description=_DESCRIPTION)
   parser.add_argument('benchmark_list_file', type=file,
                       help='a file listing benchmarks to run')
   parser.add_argument('--save-traces', action='store_true',
@@ skipping 17 matching lines @@
 
   succeeded = True
   for benchmark_spec in benchmark_list:
     name = benchmark_spec['name']
     app = benchmark_spec['app']
     duration = benchmark_spec['duration']
     shell_args = benchmark_spec.get('shell-args', []) + common_shell_args
     measurements = benchmark_spec['measurements']
     _run_benchmark(shell, shell_args, name, app, duration, measurements,
                    cold_start=True, verbose=script_args.verbose,
+                   android=script_args.android,
                    save_traces=script_args.save_traces)
     _run_benchmark(shell, shell_args, name, app, duration, measurements,
                    cold_start=False, verbose=script_args.verbose,
+                   android=script_args.android,
                    save_traces=script_args.save_traces)
 
   return 0 if succeeded else 1
 
 if __name__ == '__main__':
   sys.exit(main())