[iOS] Rename iOS-specific InfoBarIOS files to match class names.

The filename should match the name of the class defined within.  By
naming these files infobar.[h/mm], we were interfering with XCode's
indexing and making the "⌘ + shift + O" shortcut difficult to use.

Bug: none
Change-Id: Ibd976cae6e82c222e8380f3cd3eeec1c086f4735
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1949103
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Auto-Submit: Kurt Horimoto <kkhorimoto@chromium.org>
Commit-Queue: Kurt Horimoto <kkhorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#721175}
17 files changed