When using the zero color mask workaround in StateManager9, the blend state and
blend equation were being modified. This caused inconsistant state if the
workaround stopped being used in subsequent draw calls. To deal with this
issue, dirty the BLEND_ENABLED and BLEND_EQUATION states when the COLOR_MASK
changes and dirty the COLOR_MASK state wheneither BLEND_ENABLED or
BLEND_EQUATION changes.
BUG=597107
Change-Id: I50ed119c31d40b1c19fc5276b1407342a8a0bd16
Reviewed-on: https://chromium-review.googlesource.com/343540Reviewed-by: Geoff Lang <geofflang@chromium.org>
