Reland of Make a single GrSingleOwner in GrContext (patchset #1 id:1 of https://codereview.chromium.org/1565303003/ )

Reason for revert:
trying again

Original issue's description:
> Revert of Make a single GrSingleOwner in GrContext (patchset #3 id:40001 of https://codereview.chromium.org/1563703004/ )
>
> Reason for revert:
> breaking asan
>
> Original issue's description:
> > Make a single GrSingleOwner in GrContext
> >
> > TBR=bsalomon@google.com
> > BUG=skia:
> > GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1563703004
> >
> > Committed: https://skia.googlesource.com/skia/+/f9bc796e0dbd31674c22b34761913ee6e8fdd66a
>
> TBR=robertphillips@google.com,joshualitt@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/94da292e39db0d41da08b1d6055ca5e0d6b498cc

TBR=robertphillips@google.com,joshualitt@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1572653002
diff --git a/include/private/GrSingleOwner.h b/include/private/GrSingleOwner.h
index dea982e..64e63d3 100644
--- a/include/private/GrSingleOwner.h
+++ b/include/private/GrSingleOwner.h
@@ -48,6 +48,8 @@
      SkThreadID fOwner;    // guarded by fMutex
      int fReentranceCount; // guarded by fMutex
 };
+#else
+class GrSingleOwner {}; // Provide a dummy implementation so we can pass pointers to constructors
 #endif
 
 #endif