Added mgiuca and thakis as OWNERS of .git-blame-ignore-revs.

This is to reduce burden on top-level owners of approving additions to
this file, and so we can enforce somewhat of a standard bar for what
goes into the hyper-blame ignore list.

BUG=574290

Review URL: https://codereview.chromium.org/1724383002

Cr-Commit-Position: refs/heads/master@{#377223}

OWNERS

@@ -5,6 +5,8 @@ [email protected]
 [email protected]
 
 per-file .gitignore=*
+per-file [email protected]
+per-file [email protected]
 per-file [email protected]
 per-file DEPS=*
 per-file AUTHORS=*