What is Chrome doing with this "GC Event"?

Is this a site that we can check out or is it internal? I'd like to take a peek. I came across the excerpt below while googling on the Google Developers pages, Memory Analysis 101:

Object Sizes

Memory can be held by an object in two ways: directly by the object itself, and implicitly by holding references to other objects, and thus preventing them from being automatically disposed by a garbage collector (GC for short).

The size of memory that is held by the object itself is called shallow size. Typical JavaScript objects have some memory reserved for their description and for storing immediate values.

Usually, only arrays and strings can have significant shallow sizes. However, strings often have their main storage in renderer memory, exposing only a small wrapper object on the JavaScript heap.

Nevertheless, even a small object can hold a large amount of memory indirectly, by preventing other objects from being disposed by the automatic garbage collection process. The size of memory that will be freed, when the object itself is deleted, and its dependent objects made unreachable from GC roots, is called retained size.

The last bit seems to be potentially your issue.

Investigating memory issues

If you're inclined you might want to enable this feature of chrome, chrome --enable-memory-info, and take a peak behind the curtain to see what chrome is potentially getting hung up on.

Once you have Chrome running with the memory profiling enabled you’ll have access to two new properties:

window.performance.memory.totalJSHeapSize;  // currently used heap memorywindow.performance.memory.usedJSHeapSize; // total heap memory

This feature is covered in more details here.