GitLab

- Add Dictionary::at(StringPiece), which allows looking up items on a
  constant Dictionary object or reference. Also add at(size_t) and const
  variants for indexed accesses.
- Always initialize all fields. Currently the
  ParameterizedMember::member_is_inner_list is left uninitialized by its
  default constructor.

Bug: 1061139
Change-Id: Id3e523e0948ab1e93a917c89b6cc62955cc07bb9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2103397
Commit-Queue: Timothy Gu <timothygu@chromium.org>
Reviewed-by: Asanka Herath <asanka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#752349}