# Release the tab so that it can be disconnected.
self._impl = None
results.AddValue(scalar.ScalarValue(
- results.current_page, '%s.speed_index' % chart_name, 'ms', index))
+ results.current_page, '%s_speed_index' % chart_name, 'ms', index,
+ description='Speed Index. This focuses on time when visible parts of '
+ 'page are displayed and shows the time when the '
+ 'first look is "almost" composed. If the contents of the '
+ 'testing page are composed by only static resources, load '
+ 'time can measure more accurately and speed index will be '
+ 'smaller than the load time. On the other hand, If the '
+ 'contents are composed by many XHR requests with small '
+ 'main resource and javascript, speed index will be able to '
+ 'get the features of performance more accurately than load '
+ 'time because the load time will measure the time when '
+ 'static resources are loaded. If you want to get more '
+ 'detail, please refer to http://goo.gl/Rw3d5d. Currently '
+ 'there are two implementations: for Android and for '
+ 'Desktop. The Android version uses video capture; the '
+ 'Desktop one uses paint events and has extra overhead to '
+ 'catch paint events.'))
def IsFinished(self, tab):
"""Decide whether the timeline recording should be stopped.