v8binding: Treat |optional any arg = null| as v8::Null

|ScriptValue()| creates an empty ScriptValue, which corresponds
to |v8::Local<v8::Value>()| (empty handle), which will be
v8::Undefined.  It's not v8::Null.

This patch makes it v8::Null explicitly.

Change-Id: Ibf5afaff05174bb1458e86fc84fd8c8e8010a6b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1520523
Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641159}
1 file changed