Enable some profile_chrome unit tests on Trybots

systrace/profile_chrome/chrome_tracing_agent.py

Index: systrace/profile_chrome/chrome_tracing_agent.py
diff --git a/systrace/profile_chrome/chrome_tracing_agent.py b/systrace/profile_chrome/chrome_tracing_agent.py
index 4886228324f6ea8931e22a96edc05d48b8ad4cbe..fecd7af42e6935e28ca4442243104e49b5ea5166 100644
--- a/systrace/profile_chrome/chrome_tracing_agent.py
+++ b/systrace/profile_chrome/chrome_tracing_agent.py
@@ -7,10 +7,10 @@ import optparse
 import os
 import py_utils
 import re
+from profile_chrome import util
 
 from devil.android import device_errors
 from devil.android.sdk import intent
-
 from systrace import trace_result
 from systrace import tracing_agents
 
@@ -40,6 +40,9 @@ class ChromeTracingAgent(tracing_agents.TracingAgent):
 
   @staticmethod
   def GetCategories(device, package_info):
+    curr_browser = util.GetChromeProcessID(device, package_info)

[Sami, 2016/09/09 10:28:25]

I don't think the agents should be trying to start the browser. That is the
responsibility of the caller (i.e., test harness in this case).

[washingtonp, 2016/09/09 18:07:29]

Done.

+    if curr_browser == None:
+      util.StartBrowser(device, package_info)
     with device.GetLogcatMonitor() as logmon:
       device.BroadcastIntent(intent.Intent(
           action='%s.GPU_PROFILER_LIST_CATEGORIES' % package_info.package))
@@ -64,6 +67,9 @@ class ChromeTracingAgent(tracing_agents.TracingAgent):
 
   @py_utils.Timeout(tracing_agents.START_STOP_TIMEOUT)
   def StartAgentTracing(self, config, timeout=None):
+    curr_browser = util.GetChromeProcessID(self._device, self._package_info)
+    if curr_browser == None:
+      util.StartBrowser(self._device, self._package_info)
     self._categories = _ComputeChromeCategories(config)
     self._logcat_monitor.Start()
     start_extras = {'categories': ','.join(self._categories)}