[10/N] Add DIR_METADATA files to directories under //third_party/blink/web_tests/external

Generate DIR_METADATA files and remove metadata from OWNERS
files for directories under //third_party/blink/web_tests/external.

Bug: 1113033
Change-Id: I23683087348b268c9bd13a06a509ffc119d3811e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2573127Reviewed-by: Yoav Weiss <yoavweiss@chromium.org>
Commit-Queue: Yoav Weiss <yoavweiss@chromium.org>
Auto-Submit: Josip Sokcevic <sokcevic@google.com>
Cr-Commit-Position: refs/heads/master@{#833892}

third_party/blink/web_tests/external/wpt/webmessaging/DIR_METADATA

+monorail {
+  component: "Blink>Messaging"
+}

third_party/blink/web_tests/external/wpt/webmessaging/OWNERS

-# COMPONENT: Blink>Messaging
 mek@chromium.org

third_party/blink/web_tests/external/wpt/webrtc/DIR_METADATA

+monorail {
+  component: "Blink>WebRTC"
+}
+wpt {
+  notify: YES
+}

third_party/blink/web_tests/external/wpt/webrtc/OWNERS

-# COMPONENT: Blink>WebRTC
-# WPT-NOTIFY: true
 hbos@chromium.org
 hta@chromium.org
 guidou@chromium.org

third_party/blink/web_tests/external/wpt/websockets/DIR_METADATA

+monorail {
+  component: "Blink>Network>WebSockets"
+}
+team_email: "blink-network-dev@chromium.org"

third_party/blink/web_tests/external/wpt/websockets/OWNERS

-# TEAM: blink-network-dev@chromium.org
-# COMPONENT: Blink>Network>WebSockets

third_party/blink/web_tests/external/wpt/webstorage/DIR_METADATA

+monorail {
+  component: "Blink>Storage>DOMStorage"
+}
+team_email: "storage-dev@chromium.org"
+wpt {
+  notify: YES
+}

third_party/blink/web_tests/external/wpt/webstorage/OWNERS

-# TEAM: storage-dev@chromium.org
-# COMPONENT: Blink>Storage>DOMStorage
-# WPT-NOTIFY: true
 jsbell@chromium.org
 mek@chromium.org

third_party/blink/web_tests/external/wpt/webusb/DIR_METADATA

+monorail {
+  component: "Blink>USB"
+}
+team_email: "webusb@chromium.org"

third_party/blink/web_tests/external/wpt/webusb/OWNERS

 file://chrome/browser/usb/OWNERS
-
-# COMPONENT: Blink>USB
-# TEAM: webusb@chromium.org

third_party/blink/web_tests/external/wpt/webvtt/DIR_METADATA

+monorail {
+  component: "Blink>Media>Track"
+}
+team_email: "media-dev@chromium.org"

third_party/blink/web_tests/external/wpt/webvtt/OWNERS

-# TEAM: media-dev@chromium.org
-# COMPONENT: Blink>Media>Track
 msisov@igalia.com

third_party/blink/web_tests/external/wpt/webxr/DIR_METADATA

+monorail {
+  component: "Blink>WebXR"
+}
+team_email: "xr-dev@chromium.org"
+wpt {
+  notify: YES
+}

third_party/blink/web_tests/external/wpt/webxr/OWNERS

 file://third_party/blink/renderer/modules/xr/OWNERS
-
-# TEAM: xr-dev@chromium.org
-# COMPONENT: Blink>WebXR
-# WPT-NOTIFY: true

third_party/blink/web_tests/external/wpt/workers/DIR_METADATA

+monorail {
+  component: "Blink>Workers"
+}
+team_email: "worker-dev@chromium.org"

third_party/blink/web_tests/external/wpt/workers/OWNERS

-# TEAM: worker-dev@chromium.org
-# COMPONENT: Blink>Workers

third_party/blink/web_tests/external/wpt/worklets/DIR_METADATA

+monorail {
+  component: "Blink>Workers"
+}
+team_email: "worker-dev@chromium.org"

third_party/blink/web_tests/external/wpt/worklets/OWNERS

-# TEAM: worker-dev@chromium.org
-# COMPONENT: Blink>Workers

third_party/blink/web_tests/external/wpt/x-frame-options/DIR_METADATA

+monorail {
+  component: "Blink>SecurityFeature>XFrameOptions"
+}
+team_email: "security-dev@chromium.org"

third_party/blink/web_tests/external/wpt/x-frame-options/OWNERS

-# TEAM: security-dev@chromium.org
-# COMPONENT: Blink>SecurityFeature>XFrameOptions
 mkwst@chromium.org

third_party/blink/web_tests/external/wpt/xhr/DIR_METADATA

+monorail {
+  component: "Blink>Network>XHR"
+}
+team_email: "blink-network-dev@chromium.org"

third_party/blink/web_tests/external/wpt/xhr/OWNERS

-# TEAM: blink-network-dev@chromium.org
-# COMPONENT: Blink>Network>XHR