Generate pixel shader output to match the bound framebuffer. Only generate pixel shader output variables for render targets that are currently bound. Fixes some performance issues with D3D10 cards that were slow to discard unused outputs. Fixed memory leaks in ProgramBinary by refactoring the freeing of the current state into a reset function. BUG=angle:670 Change-Id: I40f83e15724fb9a1a9ae61363a056999f1fa26d2 Reviewed-on: https://chromium-review.googlesource.com/202977 Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>