Revert[5] "replace SkXfermode obj with SkBlendMode enum in paints"

This reverts commit I0fa5c58af428f3da8565465d1219a34ef8417d9a.

Reason for revert: failing to deserialize some of the 100K

Original change's description:
> Revert[4] "replace SkXfermode obj with SkBlendMode enum in paints"
> 
> This reverts commit 2cbcd12281ee807214df094964c584c78932e10b.
> 
> BUG=skia:
> 
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2924
> 
> Change-Id: I0fa5c58af428f3da8565465d1219a34ef8417d9a
> Reviewed-on: https://skia-review.googlesource.com/2924
> Reviewed-by: Mike Reed <reed@google.com>
> Commit-Queue: Mike Reed <reed@google.com>
> 

TBR=reed@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I1805a57eef5ebcac203da5989c8539345ecf806f
Reviewed-on: https://skia-review.googlesource.com/2962
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/samplecode/SampleSlides.cpp b/samplecode/SampleSlides.cpp
index 521e9f6..5858d26 100644
--- a/samplecode/SampleSlides.cpp
+++ b/samplecode/SampleSlides.cpp
@@ -472,7 +472,7 @@
 
     p.setAlpha(0x11);
     p.setStyle(SkPaint::kFill_Style);
-    p.setBlendMode(SkBlendMode::kSrc);
+    p.setXfermodeMode(SkXfermode::kSrc_Mode);
     rastBuilder->addLayer(p);
 }
 
@@ -481,7 +481,7 @@
     rastBuilder->addLayer(p);
 
     p.setAlpha(0x40);
-    p.setBlendMode(SkBlendMode::kSrc);
+    p.setXfermodeMode(SkXfermode::kSrc_Mode);
     p.setStyle(SkPaint::kStroke_Style);
     p.setStrokeWidth(SK_Scalar1*2);
     rastBuilder->addLayer(p);
@@ -495,7 +495,7 @@
 
     p.setStyle(SkPaint::kStroke_Style);
     p.setStrokeWidth(SK_Scalar1*3/2);
-    p.setBlendMode(SkBlendMode::kClear);
+    p.setXfermodeMode(SkXfermode::kClear_Mode);
     rastBuilder->addLayer(p);
 }
 
@@ -507,7 +507,7 @@
 
     p.setAlpha(0x20);
     p.setStyle(SkPaint::kFill_Style);
-    p.setBlendMode(SkBlendMode::kSrc);
+    p.setXfermodeMode(SkXfermode::kSrc_Mode);
     rastBuilder->addLayer(p);
 }
 
@@ -517,10 +517,10 @@
     rastBuilder->addLayer(p, SkIntToScalar(3), SkIntToScalar(3));
 
     p.setAlpha(0xFF);
-    p.setBlendMode(SkBlendMode::kClear);
+    p.setXfermodeMode(SkXfermode::kClear_Mode);
     rastBuilder->addLayer(p, SK_Scalar1*3/2, SK_Scalar1*3/2);
 
-    p.setBlendMode(SkBlendMode::kSrcOver);
+    p.setXfermode(nullptr);
     rastBuilder->addLayer(p);
 }
 
@@ -531,7 +531,7 @@
     rastBuilder->addLayer(p);
 
     p.setPathEffect(SkDiscretePathEffect::Make(SK_Scalar1*4, SK_Scalar1*3));
-    p.setBlendMode(SkBlendMode::kSrcOut);
+    p.setXfermodeMode(SkXfermode::kSrcOut_Mode);
     rastBuilder->addLayer(p);
 }
 
@@ -543,7 +543,7 @@
     SkLayerRasterizer::Builder rastBuilder2;
     r5(&rastBuilder2, p);
     p.setRasterizer(rastBuilder2.detach());
-    p.setBlendMode(SkBlendMode::kClear);
+    p.setXfermodeMode(SkXfermode::kClear_Mode);
     rastBuilder->addLayer(p);
 }
 
@@ -572,11 +572,11 @@
     lattice.setScale(SK_Scalar1*6, SK_Scalar1*6, 0, 0);
     lattice.postSkew(SK_Scalar1/3, 0, 0, 0);
     p.setPathEffect(MakeDotEffect(SK_Scalar1*2, lattice));
-    p.setBlendMode(SkBlendMode::kClear);
+    p.setXfermodeMode(SkXfermode::kClear_Mode);
     rastBuilder->addLayer(p);
 
     p.setPathEffect(nullptr);
-    p.setBlendMode(SkBlendMode::kSrcOver);
+    p.setXfermode(nullptr);
     p.setStyle(SkPaint::kStroke_Style);
     p.setStrokeWidth(SK_Scalar1);
     rastBuilder->addLayer(p);
@@ -590,11 +590,11 @@
     lattice.setScale(SK_Scalar1, SK_Scalar1*6, 0, 0);
     lattice.postRotate(SkIntToScalar(30), 0, 0);
     p.setPathEffect(SkLine2DPathEffect::Make(SK_Scalar1*2, lattice));
-    p.setBlendMode(SkBlendMode::kClear);
+    p.setXfermodeMode(SkXfermode::kClear_Mode);
     rastBuilder->addLayer(p);
 
     p.setPathEffect(nullptr);
-    p.setBlendMode(SkBlendMode::kSrcOver);
+    p.setXfermode(nullptr);
     p.setStyle(SkPaint::kStroke_Style);
     p.setStrokeWidth(SK_Scalar1);
     rastBuilder->addLayer(p);