Migrate to @interface and @impl ChromeMatchers for chrome_matchers.h/mm

Bug: 922813
Change-Id: Ia2e2ab97c670ea174981544e5ec5c38abca71b15
Reviewed-on: https://chromium-review.googlesource.com/c/1419039
Commit-Queue: Lindsay Pasricha <lindsayw@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631091}
5 files changed