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

mojo/devtools/common/devtoolslib/android_shell.py

 # Copyright 2014 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.
 
 import atexit
 import hashlib
 import json
 import logging
 import os
 import os.path
@@ skipping 181 matching lines @@
       self.adb_running_as_root = False
 
     return self.adb_running_as_root
 
   def _is_shell_package_installed(self):
     # Adb should print one line if the package is installed and return empty
     # string otherwise.
     return len(subprocess.check_output(self._adb_command([
         'shell', 'pm', 'list', 'packages', _MOJO_SHELL_PACKAGE_NAME]))) > 0
 
+  @staticmethod
+  def get_tmp_dir_path():
+    """Returns a path to a cache directory owned by the shell where temporary
+    files can be stored.
+    """
+    return '/data/data/%s/cache/tmp/' % _MOJO_SHELL_PACKAGE_NAME
+
+  def pull_file(self, device_path, destination_path, remove_original=False):
+    """Copies or moves the specified file on the device to the host."""
+    subprocess.check_call(self._adb_command([
+        'pull', device_path, destination_path]))
+    if remove_original:
+      subprocess.check_call(self._adb_command([
+          'shell', 'rm', device_path]))
+
   def check_device(self, require_root=False):
     """Verifies if the device configuration allows adb to run.
 
     If a target device was indicated in the constructor, it checks that the
     device is available. Otherwise, it checks that there is exactly one
     available device.
 
     Returns:
       A tuple of (result, msg). |result| is True iff if the device is correctly
       configured and False otherwise. |msg| is the reason for failure if
@@ skipping 209 matching lines @@
           Results.output = rf.read()
 
     run_thread = threading.Thread(target=do_run)
     run_thread.start()
     run_thread.join(timeout)
 
     if run_thread.is_alive():
       self.stop_shell()
       return None, Results.output, True
     return None, Results.output, False