Use range-based for more often.

This also fixes a few cases of not using =default, and uses STL algorithms where
it makes sense.

Bug: 940126
Change-Id: I509e832644893e409e37ff4550d594a0f3455c07
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1625898
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Robert Liao <robliao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662479}
26 files changed