skpbench: filter out junk spewed by Pixel C driver

tools/skpbench/_hardware.py

 # Copyright 2016 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import time
 
 class Hardware:
   """Locks down and monitors hardware for benchmarking.
 
@@ skipping 11 matching lines @@
 
   def __init__(self):
     self.warmup_time = 0
 
   def __enter__(self):
     return self
 
   def __exit__(self, exception_type, exception_value, traceback):
     pass
 
+  def filter_line(self, line):
+    """Returns False if the provided output line can be suppressed."""
+    return True
+
   def sanity_check(self):
     """Raises a HardwareException if any hardware state is not as expected."""
     pass
 
   def print_debug_diagnostics(self):
     """Prints any info that may help improve or debug hardware monitoring."""
     pass
 
   def sleep(self, sleeptime):
     """Puts the hardware into a resting state for a fixed amount of time."""
@@ skipping 42 matching lines @@
 
   @staticmethod
   def check_all(expectations, stringvalues):
     if len(stringvalues) != len(expectations):
       raise Exception("unexpected reading from hardware gauges "
                       "(expected %i values):\n%s" %
                       (len(expectations), '\n'.join(stringvalues)))
 
     for value, expected in zip(stringvalues, expectations):
       expected.check(value)