Enable some profile_chrome unit tests on Trybots

systrace/profile_chrome/atrace_tracing_agent_unittest.py

 # Copyright 2014 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.
 
 from profile_chrome import agents_unittest
 from profile_chrome import atrace_tracing_agent
+from systrace import decorators
 
 
 class AtraceAgentTest(agents_unittest.BaseAgentTest):
+  @decorators.ClientOnlyTest
   def testGetCategories(self):
     categories = \
         atrace_tracing_agent.AtraceAgent.GetCategories(self.device)
     self.assertTrue(categories)
     assert 'gfx' in ' '.join(categories)
 
+  # TODO(washingtonp): This test throws an error on the Trybot servers when
+  # running profile_chrome's atrace agent. Once systrace uses profile_chrome's
+  # agent instead, this test may not longer need to be disabled.
+  @decorators.Disabled
   def testTracing(self):
     categories = 'gfx,input,view'
     ring_buffer = False
     agent = atrace_tracing_agent.AtraceAgent(self.device,
                                              ring_buffer)
 
     try:
       agent.StartAgentTracing(atrace_tracing_agent.AtraceConfig(categories,
           self.device, ring_buffer))
     finally:
       agent.StopAgentTracing()
     result = agent.GetResults()
 
     self.assertFalse(agent.IsTracingOn())
     self.assertTrue('CPU#' in result.raw_data)