Stop adding RawResources to MemoryCache

This CL stops adding RawResources to MemoryCache, mainly for a step for
code simplification. Most of RawResources are already not added sto
MemoryCache, so I expect the performance loss is acceptable. This CL
will allow us to remove revalidation code from RawResource, which is
beneficial for code simplicity and security.

Some inspector code assumes that resources loaded by
InspectorResourceContentLoader are cached. This CL breaks the
assumption. Instead, this CL makes CachedResource  search for a
resource also in the InspectorResourceContentLoader.

Bug: 652228
Change-Id: Ie9bdcd33248038d99b1dcdb59085cf3811b3bd87
Reviewed-on: https://chromium-review.googlesource.com/513764
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Hiroshige Hayashizaki <hiroshige@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#492346}
7 files changed