Fix scissor for functor invocation

 Bug: 10677765
 enableScissor() must precede setScissorFromClip() as
 otherwise setScissorFromClip() doesn't do anything.
 Also make sure to call setScissorFromClip() if
 enableScissor() returns true as enableScissor() calls
 resetScissor() if the scissor state has changed.

Change-Id: I9226b20bb256c92066aae344e4e6407540b6eae9