Update systrace and profile_chrome's default agent behavior

systrace/profile_chrome/main.py

Index: systrace/profile_chrome/main.py
diff --git a/systrace/profile_chrome/main.py b/systrace/profile_chrome/main.py
index 117e08d2375dfbf888ba4cbff7e863a9af92b652..b654b884b57593be016e25718195b2bc6aebf731 100755
--- a/systrace/profile_chrome/main.py
+++ b/systrace/profile_chrome/main.py
@@ -99,6 +99,10 @@ When in doubt, just try out --trace-frame-viewer.
   options.device = device
   options.package_info = package_info
 
+  # Include Chrome categories by default in profile_chrome.
+  if not options.chrome_categories:
+    options.chrome_categories = chrome_tracing_agent.DEFAULT_CHROME_CATEGORIES
+
   if options.chrome_categories in ['list', 'help']:
     ui.PrintMessage('Collecting record categories list...', eol='')
     record_categories = []