Add a snapshot of flutter/engine/src/build to our sdk

build/android/pylib/utils/device_temp_file.py

+# Copyright 2013 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.
+
+"""A temp file that automatically gets pushed and deleted from a device."""
+
+# pylint: disable=W0622
+
+import random
+import time
+
+from pylib import cmd_helper
+from pylib.device import device_errors
+
+
+class DeviceTempFile(object):
+  def __init__(self, adb, suffix='', prefix='temp_file', dir='/data/local/tmp'):
+    """Find an unused temporary file path in the devices external directory.
+
+    When this object is closed, the file will be deleted on the device.
+
+    Args:
+      adb: An instance of AdbWrapper
+      suffix: The suffix of the name of the temp file.
+      prefix: The prefix of the name of the temp file.
+      dir: The directory on the device where to place the temp file.
+    """
+    self._adb = adb
+    # make sure that the temp dir is writable
+    self._adb.Shell('test -d %s' % cmd_helper.SingleQuote(dir))
+    while True:
+      self.name = '{dir}/{prefix}-{time:d}-{nonce:d}{suffix}'.format(
+        dir=dir, prefix=prefix, time=int(time.time()),
+        nonce=random.randint(0, 1000000), suffix=suffix)
+      self.name_quoted = cmd_helper.SingleQuote(self.name)
+      try:
+        self._adb.Shell('test -e %s' % self.name_quoted)
+      except device_errors.AdbCommandFailedError:
+        break # file does not exist
+
+    # Immediately touch the file, so other temp files can't get the same name.
+    self._adb.Shell('touch %s' % self.name_quoted)
+
+  def close(self):
+    """Deletes the temporary file from the device."""
+    # ignore exception if the file is already gone.
+    try:
+      self._adb.Shell('rm -f %s' % self.name_quoted)
+    except device_errors.AdbCommandFailedError:
+      # file does not exist on Android version without 'rm -f' support (ICS)
+      pass
+
+  def __enter__(self):
+    return self
+
+  def __exit__(self, type, value, traceback):
+    self.close()