Add README.chromium for third_party/khronos

This is required by tools/licenses.py in chromium in order
to correctly aggregate all license files in use.

Bug: chromium:1355665
Change-Id: Idb6b3a5c8c38b6880298a2c659c5b6e356e12694
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/106414
Reviewed-by: David Neto <dneto@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Zhenyao Mo <zmo@google.com>
Commit-Queue: David Neto <dneto@google.com>
diff --git a/third_party/khronos/README.chromium b/third_party/khronos/README.chromium
new file mode 100644
index 0000000..bbe8767
--- /dev/null
+++ b/third_party/khronos/README.chromium
@@ -0,0 +1,5 @@
+Name: Khronos EGL
+Short Name: khronos
+URL: https://www.khronos.org
+License: Apache 2.0
+License File: LICENSE
\ No newline at end of file