Add missing import in chrome_startup_controller.py.

tools/profile_chrome/chrome_startup_controller.py

Index: tools/profile_chrome/chrome_startup_controller.py
diff --git a/tools/profile_chrome/chrome_startup_controller.py b/tools/profile_chrome/chrome_startup_controller.py
index d685502eb50d53f3e1f9963ffeb4ba7d7479f44c..87353e3fbf4050c8b8c70c9246e268f54bcedb74 100644
--- a/tools/profile_chrome/chrome_startup_controller.py
+++ b/tools/profile_chrome/chrome_startup_controller.py
@@ -7,6 +7,7 @@ import re
 import time
 
 from pylib import flag_changer
+from pylib.device import intent
 from pylib.perf import cache_control
 
 from profile_chrome import controllers
@@ -39,7 +40,7 @@ class ChromeStartupTracingController(controllers.BaseController):
             package=self._package_info.package,
             activity=self._package_info.activity,
             data=self._url,
-            extras={'create_new_tab' : True}))
+            extras={'create_new_tab' : True}), blocking=True)
 
   def _TearDownTracing(self):
     changer = flag_changer.FlagChanger(