Initial (Prototype) Implementation of HTTPS image redirects.

Uses the ResourceRequest pointer in URLLoaderThrottle to redirect image
subresources on a page to a compressed version of the same resource.
This initial implementation will return a 200 when it successfully swaps
compressed version and a 307 when it needs to fall back onto the
original uncompressed resource.  It currently only handles those 2

This is a prototype implementation and is behind a flag.

Bug: 960513
Change-Id: I1d47e9f958a92e1ffb970d6852cdcab2acd9e698
Commit-Queue: Sean Harrison <>
Reviewed-by: Tarun Bansal <>
Reviewed-by: John Abd-El-Malek <>
Reviewed-by: Robert Ogden <>
Cr-Commit-Position: refs/heads/master@{#661421}
17 files changed