The image below shows a close up of the timeline panel. Each thread’s
execution is shown in its own row, with time increasing to the right. Each method
is shown in another color (colors are reused in a round-robin fashion starting
with the methods that have the most inclusive time). The thin lines underneath
the first row show the extent (entry to exit) of all the calls to the selected
method. The method in this case is LoadListener.nativeFinished() and it was
selected in the profile view.