Revert[8] "replace SkXfermode obj with SkBlendMode enum in paints"

include/core/SkPaint.h

Index: include/core/SkPaint.h
diff --git a/include/core/SkPaint.h b/include/core/SkPaint.h
index e28d2fc92d59db56603f43860cf9e23fb82f95d4..ddc90ae19c7877fae6ce25bfae23eb3e45a4b7de 100644
--- a/include/core/SkPaint.h
+++ b/include/core/SkPaint.h
@@ -8,11 +8,14 @@
 #ifndef SkPaint_DEFINED
 #define SkPaint_DEFINED
 
+#include "SkBlendMode.h"
 #include "SkColor.h"
 #include "SkFilterQuality.h"
 #include "SkMatrix.h"
 #include "SkXfermode.h"
 
+//#define SK_SUPPORT_LEGACY_XFERMODE_OBJECT
+
 class SkAutoDescriptor;
 class SkAutoGlyphCache;
 class SkColorFilter;
@@ -525,12 +528,13 @@ public:
 #endif
     void setColorFilter(sk_sp<SkColorFilter>);
 
+#ifdef SK_SUPPORT_LEGACY_XFERMODE_OBJECT
     /** Get the paint's xfermode object.
         <p />
       The xfermode's reference count is not affected.
         @return the paint's xfermode (or NULL)
     */
-    SkXfermode* getXfermode() const { return fXfermode.get(); }
+    SkXfermode* getXfermode() const;
 
     /** Set or clear the xfermode object.
         <p />
@@ -552,6 +556,11 @@ public:
         the paint's xfermode is set to null.
      */
     SkXfermode* setXfermodeMode(SkXfermode::Mode);
+#endif
+
+    SkBlendMode getBlendMode() const { return (SkBlendMode)fBlendMode; }
+    bool isSrcOver() const { return (SkBlendMode)fBlendMode == SkBlendMode::kSrcOver; }
+    void setBlendMode(SkBlendMode mode) { fBlendMode = (unsigned)mode; }
 
     /** Get the paint's patheffect object.
         <p />
@@ -1090,7 +1099,6 @@ private:
     sk_sp<SkTypeface>     fTypeface;
     sk_sp<SkPathEffect>   fPathEffect;
     sk_sp<SkShader>       fShader;
-    sk_sp<SkXfermode>     fXfermode;
     sk_sp<SkMaskFilter>   fMaskFilter;
     sk_sp<SkColorFilter>  fColorFilter;
     sk_sp<SkRasterizer>   fRasterizer;
@@ -1103,6 +1111,7 @@ private:
     SkColor         fColor;
     SkScalar        fWidth;
     SkScalar        fMiterLimit;
+    uint32_t        fBlendMode; // just need 5-6 bits for SkXfermode::Mode
     union {
         struct {
             // all of these bitfields should add up to 32