GitLab

Add a new content::URLDataSource (TelemetryExtensionUntrustedSource) to
load the TelemetryExtension's untrusted resources from disk.

Bug: b:156583406, 1085330
Test: added browsertests

Change-Id: I7453c4740ee1a7c9c9240f106461735f018bfc32
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2277735Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Reviewed-by: Oleh Lamzin <lamzin@google.com>
Commit-Queue: Mahmoud Gawad <mgawad@google.com>
Cr-Commit-Position: refs/heads/master@{#792582}