Remove the child frame check in recalcLifecycle

The reason this was in place was due to out of order CDP events.
Before PR #555, there was a slim chance that the root frame would
receive lifecycle events before its child frames. This is now not the
case and we can see after extensive stress tests that the child frame
first receives CDP events and then the root/main frame.

common/frame.go

@@ -200,25 +200,6 @@ func (f *Frame) recalculateLifecycle() {
 	}
 	f.lifecycleEventsMu.RUnlock()
 
-	// Only consider a life cycle event as fired if it has triggered for all of subtree.
-	f.childFramesMu.RLock()
-	{
-		for child := range f.childFrames {
-			cf := child.(*Frame)
-			// a precaution for preventing a deadlock in *Frame.childFramesMu
-			if cf == f {
-				continue
-			}
-			cf.recalculateLifecycle()
-			for k := range events {
-				if !cf.hasSubtreeLifecycleEventFired(k) {
-					delete(events, k)
-				}
-			}
-		}
-	}
-	f.childFramesMu.RUnlock()
-
 	// Check if any of the fired events should be considered fired when looking at the entire subtree.
 	mainFrame := f.manager.MainFrame()
 	for k := range events {