[DirectoryOwnership] Add TEAM/COMPONENT into OWNERS files.

We are adding COMPONENT/TEAM information into OWNERS file. Please help us to
verify the added TEAM/COMPONENT or suggest the correct TEAM/COMPONENT in your
OWNERS files. Thanks.

Proposal to add TEAM/COMPONENT information into OWNERS files
http://bit.ly/add-team-component-proposal
Proposal about how to get suggested component for directory.
http://bit.ly/directory-mapping-proposal
TEAM-COMPONENT mapping
http://bit.ly/component-team-mapping

Additional Information:
Component lists
https://bugs.chromium.org/p/chromium/adminComponents

BUG=679905

Review-Url: https://codereview.chromium.org/2707163003
Cr-Original-Commit-Position: refs/heads/master@{#451895}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: e63ee2d8631859f96c552a203469b13a3fcceaee

config/mac/OWNERS

@@ -1,2 +1,4 @@
 rsesek@chromium.org
 sdefresne@chromium.org
+
+# COMPONENT: Build