[Android] Switch all subprocess.Popen calls to use a temporary file instead of PIPE.

build/android/pylib/android_commands.py

 # Copyright (c) 2012 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.
 
 """Provides an interface to communicate with the device via the adb command.
 
 Assumes adb binary is currently on system path.
 """
 
 import collections
@@ skipping 186 matching lines @@
         Otherwise commands are sent to all attached devices.
   """
 
   def __init__(self, device=None):
     self._adb = adb_interface.AdbInterface()
     if device:
       self._adb.SetTargetSerial(device)
     self._device = device
     self._logcat = None
     self.logcat_process = None
+    self._logcat_tmpoutfile = None
     self._pushed_files = []
     self._device_utc_offset = self.RunShellCommand('date +%z')[0]
     self._md5sum_path = ''
     self._external_storage = ''
     self._util_wrapper = ''
 
   def Adb(self):
     """Returns our AdbInterface to avoid us wrapping all its methods."""
     return self._adb
 
@@ skipping 731 matching lines @@
     StopRecordingLogcat or SearchLogcatRecord following the tests.
 
     Args:
       clear: True if existing log output should be cleared.
       filters: A list of logcat filters to be used.
     """
     if clear:
       self._adb.SendCommand('logcat -c')
     logcat_command = 'adb %s logcat -v threadtime %s' % (self._adb._target_arg,
                                                          ' '.join(filters))
+    self._logcat_tmpoutfile = tempfile.TemporaryFile(bufsize=0)
     self.logcat_process = subprocess.Popen(logcat_command, shell=True,
-                                           stdout=subprocess.PIPE)
+                                           stdout=self._logcat_tmpoutfile)
 
   def StopRecordingLogcat(self):
     """Stops an existing logcat recording subprocess and returns output.
 
     Returns:
       The logcat output as a string or an empty string if logcat was not
       being recorded at the time.
     """
     if not self.logcat_process:
       return ''
     # Cannot evaluate directly as 0 is a possible value.
     # Better to read the self.logcat_process.stdout before killing it,
     # Otherwise the communicate may return incomplete output due to pipe break.
     if self.logcat_process.poll() is None:
       self.logcat_process.kill()
-    (output, _) = self.logcat_process.communicate()
+    self.logcat_process.wait()
     self.logcat_process = None
+    self._logcat_tmpoutfile.seek(0)
+    output = self._logcat_tmpoutfile.read()
+    self._logcat_tmpoutfile.close()
     return output
 
   def SearchLogcatRecord(self, record, message, thread_id=None, proc_id=None,
                          log_level=None, component=None):
     """Searches the specified logcat output and returns results.
 
     This method searches through the logcat output specified by record for a
     certain message, narrowing results by matching them against any other
     specified criteria.  It returns all matching lines as described below.
 
@@ skipping 281 matching lines @@
   """
   def __init__(self, output):
     self._output = output
 
   def write(self, data):
     data = data.replace('\r\r\n', '\n')
     self._output.write(data)
 
   def flush(self):
     self._output.flush()