Rename ScriptPromiseResolverWithContext to ScriptPromiseResolver.

I removed ScriptPromiseResolver at r176589.
This CL renames ScriptPromiseResolverWithContext to ScriptPromiseResolver.

BUG=386479

Review URL: https://codereview.chromium.org/350313002

git-svn-id: svn://svn.chromium.org/blink/trunk@176914 bbb929c8-8fbe-4397-9dbb-9b2b20218538