Run clang-tidy modernize-use-equals-{delete,default} on //base headers

This CL only touches base headers (the headers were accidentally
excluded from the previous change to cc files).

This change was done using clang-tidy as described here:
https://chromium.googlesource.com/chromium/src/+/lkcr/docs/clang_tidy.md

BUG=778959,778957

Change-Id: I4d3b4ca1218b835a671c2e0c8f31c2b528e25a0c
Reviewed-on: https://chromium-review.googlesource.com/813316
Reviewed-by: Daniel Cheng <[email protected]>
Commit-Queue: Chris Watkins <[email protected]>
Cr-Commit-Position: refs/heads/master@{#523687}
45 files changed