Revert of Remove a scoped_refptr<>::swap overload (patchset #4 id:60001 of https://codereview.chromium.org/2723083004/ )

Reason for revert:
Broke https://build.chromium.org/p/chromium.android/builders/Android%20x64%20Builder%20%28dbg%29/builds/15131

Original issue's description:
> Remove a scoped_refptr<>::swap overload
>
> A scoped_refptr<>::swap overload is used to insert or remove the internal
> pointer without manipulating the ref count. That functionality should not
> be exposed, or at least, should be exposed separately with better name.
>
> This CL removes the swap() overload, and rewrites callers without swap().
>
> Review-Url: https://codereview.chromium.org/2723083004
> Cr-Commit-Position: refs/heads/master@{#455407}
> Committed: https://chromium.googlesource.com/chromium/src/+/511c810d540422faf221bd82a4532313cabcc4c4

TBR=dcheng@chromium.org,jkarlin@chromium.org,xhwang@chromium.org,tzik@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2732063005
Cr-Commit-Position: refs/heads/master@{#455456}
3 files changed