[DirectoryOwnership] Add TEAM/COMPONENT into OWNERS files.

Adding COMPONENT/TEAM information into OWNERS file.

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:
List of components
https://bugs.chromium.org/p/chromium/adminComponents

BUG=679905
R=wfh@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2703443002
Cr-Commit-Position: refs/heads/master@{#468246}

chrome/browser/resources/plugin_metadata/OWNERS

 bauerb@chromium.org
 jschuh@chromium.org
 wfh@chromium.org
+
+# COMPONENT: Internals>Plugins

components/metrics/leak_detector/OWNERS

@@ -5,3 +5,5 @@ wfh@chromium.org
 # introducing new sandbox escapes.
 per-file *.mojom=set noparent
 per-file *.mojom=file://ipc/SECURITY_OWNERS
+
+# COMPONENT: Internals>Metrics

third_party/fips181/OWNERS

 gcasto@chromium.org
 wfh@chromium.org
+
+# TEAM: chromium-dev@chromium.org
+# COMPONENT: UI>Browser>Passwords>Generation

third_party/tcmalloc/OWNERS

 jar@chromium.org
 wfh@chromium.org
+
+# COMPONENT: Internals>Core