Add WrapRefCounted() which is a better named version of
make_scoped_refptr(). The new name matches the MakeUnique/WrapUnique
convention already established. Update a subset of callsites to use the
WrapRefCounted() or MakeRefCounted<T>() if possible.

Other callsites will be updated in a followup CL and make_scoped_refptr
will be deleted.

Bug: 765333
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Iea443d3d60f7b158b4bbbc0f43f5c3b4fad1c079
Reviewed-on: https://chromium-review.googlesource.com/684557


Commit-Queue: kylechar <kylechar@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#504435}