Add ScriptPromiseResolver RawPtr overloads.

In an Oilpan setting, promises may now be passed RawPtr<> values
instead of RefPtr<>s. Accommodate such use by adding the needed
reject() + resolve() overloads.

(This change has been extricated from

  https://codereview.chromium.org/153083006

which we're holding off on in its entirety for the time being.)

R=haraken@chromium.org
BUG=340522

Review URL: https://codereview.chromium.org/148513008

git-svn-id: svn://svn.chromium.org/blink/trunk@166840 bbb929c8-8fbe-4397-9dbb-9b2b20218538