Revert of Make all blending up to GrOptDrawState be handled by the xp/xp factory. (patchset #7 id:140001 of https://codereview.chromium.org/759713002/)

Reason for revert:
break many gm's

Original issue's description:
> Make all blending up to GrOptDrawState be handled by the xp/xp factory.
>
> In this cl the blending information is extracted for the xp and stored in the ODS
> which is then used as it currently is. In the follow up cl, an XP backend will be added
> and at that point all blending work will take place inside XP's.
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/7c66342a399b529634bed0fabfaa562db2c0dbd4

TBR=bsalomon@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/766653008
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index c0439f5..b4b24d9 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -9,7 +9,6 @@
 
 #include "effects/GrBicubicEffect.h"
 #include "effects/GrDashingEffect.h"
-#include "effects/GrPorterDuffXferProcessor.h"
 #include "effects/GrTextureDomain.h"
 #include "effects/GrSimpleTextureEffect.h"
 
@@ -674,7 +673,7 @@
         // code path may not be taken. So we use a dst blend coeff of ISA. We
         // could special case AA draws to a dst surface with known alpha=0 to
         // use a zero dst coeff when dual source blending isn't available.
-        tempPaint.setPorterDuffXPFactory(kOne_GrBlendCoeff, kISC_GrBlendCoeff);
+        tempPaint.setBlendFunc(kOne_GrBlendCoeff, kISC_GrBlendCoeff);
     }
 
     GrContext::AutoMatrix am;