Bug: 5332296
Removed dead code in SQLiteCursor related to the use of a background
query thread. This code could result in CursorWindows being modified
concurrently or used after free. This code is broken, unused and
is just in the way.
Added comments to explain how CursorWindow ownership is
supposed to work for AbstractWindowedCursors. (There are still cases
where cursor windows get dropped on the floor without being closed.
Those will be taken care of in a subsequent patch.)
Cleaned up SQLiteQuery.fillWindow to eliminate duplicate code and
remove bits that were only needed for background loading, like
returning -1.
Change-Id: I03e8e2e73ff0c11df76d63f57df4c5ada06ae1cb
7ce745248d