GitLab

ExtensionCacheDelegate has only one concrete chromeos specific
implementation: ChromeOSExtensionCacheDelegate. Pull all methods
into that class and delete ExtensionCacheDelegate.

Bug: None
Change-Id: Ibdcfad8d45d7c84039ddf0244312ccdd5b047a64
Reviewed-on: https://chromium-review.googlesource.com/c/1257900
Commit-Queue: Istiaque Ahmed <lazyboy@chromium.org>
Reviewed-by: Toni Baržić <tbarzic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596399}