If the user is loading resources straight from the disk with the
binary shader cache, they shouldn't need to load the compiler DLL
at all. Note: might be a good idea to track more statistics here.

BUG=angleproject:1014

Change-Id: Ie75dcce3eb249347c545f1bbca7d0977df7addee
Reviewed-on: https://chromium-review.googlesource.com/282554Reviewed-by: Kenneth Russell <kbr@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>