[Merge] User Person/People instead of User/Users everywhere profile related.

[Merge] User Person/People instead of User/Users everywhere profile related.

Previously we were only doing this if the --new-avatar-menu was flipped.
This is a two-part CL. This CL removes the usages of the strings, but not
the strings themselves, since that involves some renaming and I'd like
to merge this to M39.

The CL that actually removes the unused strings is:
https://codereview.chromium.org/603023004/

XIB changes: use a different string ID for the profiles menu in the menu bar.
BUG=405988
TBR=noms@chromium.org

Review URL: https://codereview.chromium.org/611033002

Cr-Commit-Position: refs/heads/master@{#297222}
(cherry picked from commit 7252caf5868751e1f9036484b5741e85a19318a9)

Committed: https://chromium.googlesource.com/chromium/src/+/af7baf974c40cd215850ea436e7661f919bc1b25

[noms (inactive), 2014-10-02 18:03:00]

Committed patchset #1 (id:1) manually as
af7baf974c40cd215850ea436e7661f919bc1b25 (presubmit successful).