Add DIR_METADATA files to //gin

Add Generate DIR_METADATA files and remove metadata from OWNERS
files for //gin.

R=jbroman@chromium.org

Bug: 1113033
Change-Id: I45578bd0888045471f4e8e4edcb6b65b4138ed8d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2453753
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Jeremy Roman <jbroman@chromium.org>
Auto-Submit: Edward Lesmes <ehmaldonado@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814461}

gin/DIR_METADATA

+# Metadata information for this directory.
+#
+# For more information on DIR_METADATA files, see:
+#   https://source.chromium.org/chromium/infra/infra/+/master:go/src/infra/tools/dirmd/README.md
+#
+# For the schema of this file, see Metadata message:
+#   https://source.chromium.org/chromium/infra/infra/+/master:go/src/infra/tools/dirmd/proto/dir_metadata.proto
+
+monorail {
+  component: "Blink>Bindings"
+}
+team_email: "blink-reviews-bindings@chromium.org"
\ No newline at end of file

gin/OWNERS

 jochen@chromium.org
 jbroman@chromium.org
 rmcilroy@chromium.org
-
-# TEAM: blink-reviews-bindings@chromium.org
-# COMPONENT: Blink>Bindings