Add hnakashima@ as OWNERS of ChromeCachedFlags.java

Change-Id: Ib0a5f6073de3d47120591dcd68707d1876e152ba
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2129899
Commit-Queue: Theresa  <twellington@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756397}

chrome/android/java/src/org/chromium/chrome/browser/OWNERS

 per-file ChromeApplication.java=agrieve@chromium.org
+per-file ChromeCachedFlags.java=hnakashima@chromium.org
 per-file ShortcutHelper.java=dominickn@chromium.org
 
 # This is For simple changes of adding/removing features.  For more structural