A Telemetry page_action that performs the "play" action on media elements.
 
Media elements can be specified by a selector attribute. If no selector is
defined then then the action attempts to play the first video element or audio
element on the page. A selector can also be 'all' to play all media elements.
 
Other attributes to use are: wait_for_playing and wait_for_ended, which forces
the action to wait until playing and ended events get fired respectively.

Modules
		telemetry.core.exceptions os telemetry.page.actions.page_action telemetry.core.util

Classes
		telemetry.page.actions.page_action.PageAction(__builtin__.object) PlayAction   class PlayAction(telemetry.page.actions.page_action.PageAction)       Method resolution order: PlayAction telemetry.page.actions.page_action.PageAction __builtin__.object Methods defined here: HasEventCompleted(self, tab, selector, event_name) RunAction(self, page, tab, previous_action) WaitForEvent(self, tab, selector, event_name, timeout) Halts play action until the selector's event is fired. WillRunAction(self, page, tab) Load the media metrics JS code prior to running the action. __init__(self, attributes=None) Methods inherited from telemetry.page.actions.page_action.PageAction: BindMeasurementJavaScript(self, tab, start_js, stop_js) Let this action determine when measurements should start and stop.   A measurement can call this method to provide the action with JavaScript code that starts and stops measurements. The action determines when to execute the provided JavaScript code, for more accurate timings.   Args:   tab: The tab to do everything on.   start_js: JavaScript code that starts measurements.   stop_js: JavaScript code that stops measurements. CanBeBound(self) If this class implements BindMeasurementJavaScript, override CanBeBound to return True so that a test knows it can bind measurements. CleanUp(self, page, tab) CustomizeBrowserOptions(self, options) Override to add action-specific options to the BrowserOptions object. RunsPreviousAction(self) Some actions require some initialization to be performed before the previous action. For example, wait for href change needs to record the old href before the previous action changes it. Therefore, we allow actions to run the previous action. An action that does this should override this to return True in order to prevent the previous action from being run twice. Data descriptors inherited from telemetry.page.actions.page_action.PageAction: __dict__ dictionary for instance variables (if defined) __weakref__ list of weak references to the object (if defined)