1786007 - Add a fake Navigation Cache to instrument it with telemetry

Status: ASSIGNED

(Core :: JavaScript Engine, task, P1)

Description

[Nicolas B. Pierron [:nbp]]

The goal of the Navigation cache is to provide a cache which can be used if the same resources are used across pages of the same website. As users are navigating pages, resources which have already been processed can simply be reused.

The hypothesis is that these resources are frequently used and needed, and justify keeping the memory around to improve the next page load.

As part of prototyping this interface, we want to measure the number of resources which are reused, while testing different time threshold for discarding the in-memory cached content. Trashing the in-memory cache might not be catastrophic for cases which can be saved on disk.