[Telemetry] fix run_benchmark crash on CrOS

telemetry/telemetry/internal/backends/chrome/chrome_browser_backend.py

Index: telemetry/telemetry/internal/backends/chrome/chrome_browser_backend.py
diff --git a/telemetry/telemetry/internal/backends/chrome/chrome_browser_backend.py b/telemetry/telemetry/internal/backends/chrome/chrome_browser_backend.py
index f5b02fb12b6163871e6036e532abd7b115dd8024..00a9895c6e1223f2c5773aceb4d4e5d63f7f6c22 100644
--- a/telemetry/telemetry/internal/backends/chrome/chrome_browser_backend.py
+++ b/telemetry/telemetry/internal/backends/chrome/chrome_browser_backend.py
@@ -139,7 +139,8 @@ class ChromeBrowserBackend(browser_backend.BrowserBackend):
         self._port,
         self._browser_target, self)
 
-  def _WaitForBrowserToComeUp(self, remote_devtools_port=None):
+  def _WaitForBrowserToComeUp(self, remote_devtools_port=None,
+                              enable_tracing=True):
     """ Wait for browser to come up.
 
     Args:
@@ -155,7 +156,7 @@ class ChromeBrowserBackend(browser_backend.BrowserBackend):
       raise exceptions.BrowserConnectionGoneException(self.browser, e)
     self._devtools_client = devtools_client_backend.DevToolsClientBackend(
         self._port, self._browser_target,
-        remote_devtools_port or self._port, self)
+        remote_devtools_port or self._port, self, enable_tracing)
 
   def _WaitForExtensionsToLoad(self):
     """ Wait for all extensions to load.