I have a large web page (internal, in development) that is taking too long to load. Specifically, loading the 2.3MB HTML page shows the styled content in ~3s, and then the browser locks up for over 20s before becoming interactive.
Using Chrome’s Timeline I can see that this is all due to script being kicked off as part of the load event:

However, when I profile the page load I see this (click for full size):

32.01 seconds are spent in some anonymous function with no associated source code. As part of that, 18.87 seconds are spent in the function “get length” (which also has no associated source code).
What is get length? Is there no better information available from the profiler about where time is being spent?
This is call to a length attribute of the form (or any other DOM element with the native length attribute.
This is an example code I used
I get the following in the Chrome profiler:
I do have an arrow beneath it to drill down through function a() though.