GitLab

External component extensions are loaded through the external provider
mechanism. These external extensions, by default, have a lower fetch
priority. For external policy extensions, we increase the priority. Do
the same for external component extensions, and add a test.

Bug: 965686

Change-Id: Ied58e08f403d574c4b6e8f7bdc484db90f926018
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1627783
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664844}