Revert "SideBySide2: Track SkipBar instances by the starting line"

This reverts commit 1df5a8f00fbe69ec3b386ed3487a2ae0c229a966.

Tracking the bar using a SortedMap is not necessary.  The skip
bars are removed automatically by CM3 now when search enters into
a skipped region.

Change-Id: Ia3194692c7a8e7c098bc97d9dc2ebd3fa89fc5ca
2 files changed