Make ShadowValue usable as a constexpr.

This makes sense since it's basically a bag of data.  I didn't try hard to make
every possible function constexpr.

I thought this would be useful to me in making some ShadowValues, but since
those are in a vector, which doesn't have a constexpr constructor, that doesn't
work.  Still, it may allow for some better-optimized code (didn't check), and
for the (rare) case when you just have one ShadowValue to do something with.

Also includes some other misc. cleanup I found at the same time.

BUG=none
TEST=none

Change-Id: Ib492fe2cffb3ce68cb1c09b628d8f1376f046092
Reviewed-on: https://chromium-review.googlesource.com/923406
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#538250}

CrOS-Libchrome-Original-Commit: e91c195b4e4b86e89e950b993ea691c276aba981
2 files changed
tree: c6760a48c5adbbc376da15f9d00e30f4e5b61514
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/