Add more OWNERS and more specialized OWNERS in Dawn

New owners:
- root: kainino
- src/dawn/native/d3d12: amaiorano
- src/dawn/native/d3d: all d3d11/d3d12 owners (amaiorano, lehoangquyen)

More specific owners who were already owners of parent directories:
- dawn frontend: kainino/lokokung
- src/dawn/native/metal: kainino/lokokung
- src/dawn/native/vulkan: bajones

No-Try: true
Change-Id: I7a1b2151c427a87746438c71c34e135e60d25002
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/234694
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Loko Kung <lokokung@google.com>
Reviewed-by: Brandon Jones <bajones@chromium.org>
Commit-Queue: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Quyen Le <lehoangquyen@chromium.org>
diff --git a/OWNERS b/OWNERS
index 892baf4..868c4c5 100644
--- a/OWNERS
+++ b/OWNERS
@@ -5,6 +5,7 @@
 geofflang@chromium.org
 jiawei.shao@intel.com
 jrprice@google.com
+kainino@chromium.org
 
 per-file DEPS=*
 per-file .gitignore=*
diff --git a/src/dawn/native/OWNERS b/src/dawn/native/OWNERS
new file mode 100644
index 0000000..bb348a0
--- /dev/null
+++ b/src/dawn/native/OWNERS
@@ -0,0 +1,4 @@
+# Dawn frontend owners - all files in this directory, excluding subdirectories:
+# https://github.com/GerritCodeReview/plugins_code-owners/blob/HEAD/resources/Documentation/path-expressions.md#simple-path-expressions
+per-file *=kainino@chromium.org
+per-file *=lokokung@google.com
diff --git a/src/dawn/native/d3d/OWNERS b/src/dawn/native/d3d/OWNERS
new file mode 100644
index 0000000..bb392f7
--- /dev/null
+++ b/src/dawn/native/d3d/OWNERS
@@ -0,0 +1,2 @@
+file:../d3d11/OWNERS
+file:../d3d12/OWNERS
diff --git a/src/dawn/native/d3d12/OWNERS b/src/dawn/native/d3d12/OWNERS
new file mode 100644
index 0000000..3bd372a
--- /dev/null
+++ b/src/dawn/native/d3d12/OWNERS
@@ -0,0 +1 @@
+amaiorano@google.com
diff --git a/src/dawn/native/metal/OWNERS b/src/dawn/native/metal/OWNERS
new file mode 100644
index 0000000..ae21c52
--- /dev/null
+++ b/src/dawn/native/metal/OWNERS
@@ -0,0 +1,2 @@
+kainino@chromium.org
+lokokung@google.com
diff --git a/src/dawn/native/vulkan/OWNERS b/src/dawn/native/vulkan/OWNERS
new file mode 100644
index 0000000..057434a
--- /dev/null
+++ b/src/dawn/native/vulkan/OWNERS
@@ -0,0 +1,2 @@
+bajones@google.com
+cwallez@google.com
diff --git a/src/dawn/wire/OWNERS b/src/dawn/wire/OWNERS
new file mode 100644
index 0000000..374bbc3
--- /dev/null
+++ b/src/dawn/wire/OWNERS
@@ -0,0 +1 @@
+lokokung@google.com