[Android] Restore filter specs to AdbWrapper.Logcat and LogcatMonitor.

build/android/pylib/device/adb_wrapper.py

Index: build/android/pylib/device/adb_wrapper.py
diff --git a/build/android/pylib/device/adb_wrapper.py b/build/android/pylib/device/adb_wrapper.py
index f29f5c7689f6505d730fa28cede6a2be6e1e11e7..7c97e6e4eb64a33a2f8615748c6379061ab4f8fc 100644
--- a/build/android/pylib/device/adb_wrapper.py
+++ b/build/android/pylib/device/adb_wrapper.py
@@ -299,14 +299,14 @@ class AdbWrapper(object):
           cmd, 'path does not specify an accessible directory in the device',
           device_serial=self._device_serial)
 
-  def Logcat(self, clear=False, dump=False, filter_spec=None,
+  def Logcat(self, clear=False, dump=False, filter_specs=None,
              logcat_format=None, timeout=None, retries=_DEFAULT_RETRIES):
     """Get an iterable over the logcat output.
 
     Args:
       clear: If true, clear the logcat.
       dump: If true, dump the current logcat contents.
-      filter_spec: If set, spec to filter the logcat.
+      filter_specs: If set, a list of specs to filter the logcat.
       logcat_format: If set, the format in which the logcat should be output.
         Options include "brief", "process", "tag", "thread", "raw", "time",
         "threadtime", and "long"
@@ -328,8 +328,8 @@ class AdbWrapper(object):
       use_iter = False
     if logcat_format:
       cmd.extend(['-v', logcat_format])
-    if filter_spec is not None:
-      cmd.append(filter_spec)
+    if filter_specs:
+      cmd.extend(filter_specs)
 
     if use_iter:
       return self._IterRunDeviceAdbCmd(cmd, timeout)