[IC] Remove Feed's custom CachedImageFetcher implementation

Bug: 864634
Change-Id: Id839586ba1ba6d32712a60df54b4e9ed15eece6f
Reviewed-on: https://chromium-review.googlesource.com/c/1306349
Commit-Queue: Brandon Wylie <wylieb@chromium.org>
Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Reviewed-by: Sky Malice <skym@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Gang Wu <gangwu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631536}
18 files changed