GitLab

 - Replace call to CallJavascriptFunctionUnsafe with
   ResolveJavascriptCallback.
 - Replace chrome.send with cr.sendWithPromise.
 - Add JS type checking.

Bug: 1028829
Change-Id: I7ed709930969e4afe153f850d96c5aa6adb7442b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2616968
Commit-Queue: John Lee <johntlee@chromium.org>
Auto-Submit: dpapad <dpapad@chromium.org>
Reviewed-by: John Lee <johntlee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841576}