dawn_wire: Add missing "strlen" in "adapter properties"

This patch adds the missing "strlen" as the "length" of the member
"name" and "driver description" in "adapter properties" so that
the generator can generate correct commands to transfer these two
strings.

BUG=dawn:160

Change-Id: I4ea385bcb3a2363a62ba48e10e85addaa7020f10
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/71440
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>
diff --git a/dawn.json b/dawn.json
index 3fc6764..b6bdb2a 100644
--- a/dawn.json
+++ b/dawn.json
@@ -97,8 +97,8 @@
         "members": [
             {"name": "vendor ID", "type": "uint32_t"},
             {"name": "device ID", "type": "uint32_t"},
-            {"name": "name", "type": "char", "annotation": "const*"},
-            {"name": "driver description", "type": "char", "annotation": "const*"},
+            {"name": "name", "type": "char", "annotation": "const*", "length": "strlen"},
+            {"name": "driver description", "type": "char", "annotation": "const*", "length": "strlen"},
             {"name": "adapter type", "type": "adapter type"},
             {"name": "backend type", "type": "backend type"}
         ]