Add trace events for some of telemetry internal functions

telemetry/telemetry/internal/actions/page_action.py

Index: telemetry/telemetry/internal/actions/page_action.py
diff --git a/telemetry/telemetry/internal/actions/page_action.py b/telemetry/telemetry/internal/actions/page_action.py
index a77d29619802cab631322047832e7591cc401c11..c279fc8c1339be9a4437a24f3b11577a4f60665b 100644
--- a/telemetry/telemetry/internal/actions/page_action.py
+++ b/telemetry/telemetry/internal/actions/page_action.py
@@ -4,8 +4,11 @@
 
 import re
 
+from py_trace_event import trace_event
+
 from telemetry import decorators
 
+
 GESTURE_SOURCE_DEFAULT = 'DEFAULT'
 GESTURE_SOURCE_MOUSE = 'MOUSE'
 GESTURE_SOURCE_TOUCH = 'TOUCH'
@@ -23,6 +26,8 @@ class PageActionFailed(Exception):
 class PageAction(object):
   """Represents an action that a user might try to perform to a page."""
 
+  __metaclass__ = trace_event.TracedMetaClass
+
   def WillRunAction(self, tab):
     """Override to do action-specific setup before
     Test.WillRunAction is called."""