Fix hang/crash in native path code

An optimization for paths is to only create a texture for the original native
Path object, and have all copies of that object use that texture. This works in
most cases, but sometimes that original path object may get destroyed (when the
SDK path object is finalized) while we are still referencing and using that object
in the DisplayList code. This causes undefined errors such as crashes and hanging
as we iterate through the operations of a destroyed (and garbage-filled) path object.

The fix is to use the existing ResourceCache to refcount the original path until
we are done with it.

Issue #6414050 Analytics Dogfood App crashes reliably on Jellybean

Change-Id: I5dbec5c069f7d6a1e68c13424f454976a7d188e9