[DirectoryOwnership] Add TEAM/COMPONENT into OWNERS files.

We are adding COMPONENT/TEAM information into OWNERS file
(autofill, etc).

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
R=estade@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2716753003
Cr-Commit-Position: refs/heads/master@{#455777}

chrome/browser/themes/OWNERS

 estade@chromium.org
 pkotwicz@chromium.org
+
+# COMPONENT: UI>Browser>Themes

chrome/browser/ui/libgtkui/OWNERS

 # You can only be a GTK owner if your name starts with "e".
 erg@chromium.org
 estade@chromium.org
+
+# COMPONENT: UI>Browser>Themes

chrome/browser/ui/views/autofill/OWNERS

 estade@chromium.org
+
+# COMPONENT: UI>Browser>Autofill

chrome/browser/ui/webui/uber/OWNERS

-estade@chromium.org