(Reland) Insert logcat as part of test result for android instrumentation tests.

build/android/pylib/android/logdog_logcat_monitor.py

Index: build/android/pylib/android/logdog_logcat_monitor.py
diff --git a/build/android/pylib/android/logdog_logcat_monitor.py b/build/android/pylib/android/logdog_logcat_monitor.py
new file mode 100644
index 0000000000000000000000000000000000000000..e244f95be964a8058524b7482644a6a69dd5afd3
--- /dev/null
+++ b/build/android/pylib/android/logdog_logcat_monitor.py
@@ -0,0 +1,89 @@
+# Copyright 2016 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 os
+import logging
+import sys
+
+from devil.android import logcat_monitor
+from devil.utils import reraiser_thread
+from pylib import constants
+
+sys.path.insert(0, os.path.abspath(os.path.join(
+    constants.DIR_SOURCE_ROOT, 'tools', 'swarming_client')))
+from libs.logdog import bootstrap # pylint: disable=import-error
+
+class LogdogLogcatMonitor(logcat_monitor.LogcatMonitor):
+  """Logcat monitor that writes logcat to a logdog stream.
+  The logdog stream client will return a url, where contains the logcat.
+  """
+  def __init__(self, adb, stream_name, clear=True, filter_specs=None):
+    super(LogdogLogcatMonitor, self).__init__(adb, clear, filter_specs)
+    self._logcat_url = ''
+    self._logdog_stream = None
+    self._stream_client = None
+    self._stream_name = stream_name
+    try:
+      self._stream_client = bootstrap.ButlerBootstrap.probe().stream_client()
+      self._logdog_stream = self._stream_client.open_text(self._stream_name)
+    except bootstrap.NotBootstrappedError as e:
+      logging.exception(
+          'Error not bootstrapped. Failed to start logdog: %s', e)
+    except ValueError as e:

[jbudorick, 2016/12/01 01:56:18]

given the number of KeyErrors that the logdog code emits, it may be prudent to
handle that here, too.

[BigBossZhiling, 2016/12/01 02:07:41]

Done.

+      logging.exception('Error cannot create stream_client: %s.', e)
+
+  def GetLogcatURL(self):
+    """Return logcat url.
+
+    The default logcat url is '', if failed to create stream_client.
+    """
+    return self._logcat_url
+
+  def Stop(self):
+    """Stops the logcat monitor.
+
+    Close the logdog stream as well.
+    """
+    super(LogdogLogcatMonitor, self)._StopRecording()
+    if self._logdog_stream:
+      try:
+        self._logcat_url = self._stream_client.get_viewer_url(self._stream_name)

[jbudorick, 2016/12/01 01:56:18]

According to the docs, this can also emit ValueError.

[BigBossZhiling, 2016/12/01 02:07:41]

Done.

+      except KeyError as e:
+        logging.exception('Error cannot get viewer url: %s', e)
+      self._logdog_stream.close()
+
+  def Start(self):
+    """Starts the logdog logcat monitor.
+
+    Clears the logcat if |clear| was set in |__init__|.
+    """
+    if self._clear:
+      self._adb.Logcat(clear=True)
+    self._StartRecording()
+
+  def _StartRecording(self):
+    """Starts recording logcat to file.
+
+    Write logcat to stream at the same time.
+    """
+    def record_to_stream():
+      if self._logdog_stream:
+        for data in self._adb.Logcat(filter_specs=self._filter_specs,
+                                     logcat_format='threadtime'):
+          if self._stop_recording_event.isSet():
+            return
+          self._logdog_stream.write(data + '\n')
+
+    self._stop_recording_event.clear()
+    if not self._record_thread:
+      self._record_thread = reraiser_thread.ReraiserThread(record_to_stream)
+      self._record_thread.start()
+
+  def Close(self):
+    """Override parent's close method."""
+    pass
+
+  def __del__(self):
+    """Override parent's delete method."""
+    pass