Revert "replace SkXfermode obj with SkBlendMode enum in paints"

This reverts commit I4fb489ba6b3f77b458f7e4a99f79c7ad10859135.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> replace SkXfermode obj with SkBlendMode enum in paints
> 
> BUG=skia:5814
> 
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2714
> 
> Change-Id: I4fb489ba6b3f77b458f7e4a99f79c7ad10859135
> Reviewed-on: https://skia-review.googlesource.com/2714
> Reviewed-by: Florin Malita <fmalita@chromium.org>
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Mike Reed <reed@google.com>
> 

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

Change-Id: I3e43f79ef5c1709929663fe63cc1f67cd78270b7
Reviewed-on: https://skia-review.googlesource.com/2871
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>

3 files changed, 25 insertions, 10 deletions

diff --git a/src/pipe/SkPipeCanvas.cpp b/src/pipe/SkPipeCanvas.cpp
index 3b636a23c0..a01237fbbb 100644
--- a/src/pipe/SkPipeCanvas.cpp
+++ b/src/pipe/SkPipeCanvas.cpp
@@ -81,6 +81,7 @@ static uint16_t compute_nondef(const SkPaint& paint, PaintUsage usage) {
         bits |= (paint.getMaskFilter()  ? kMaskFilter_NonDef : 0);
     }
 
+    bits |= (paint.getXfermode()    ? kXfermode_NonDef : 0);
     bits |= (paint.getColorFilter() ? kColorFilter_NonDef : 0);
     bits |= (paint.getImageFilter() ? kImageFilter_NonDef : 0);
     bits |= (paint.getDrawLooper()  ? kDrawLooper_NonDef : 0);
@@ -149,8 +150,15 @@ static void write_paint(SkWriteBuffer& writer, const SkPaint& paint, unsigned us
     writer.write32(packedFlags);
 
     unsigned nondef = compute_nondef(paint, (PaintUsage)usage);
+    SkXfermode::Mode mode;
+    if (SkXfermode::AsMode(paint.getXfermode(), &mode)) {
+        nondef &= ~kXfermode_NonDef;    // don't need to store a pointer since we have an enum
+    } else {
+        SkASSERT(nondef & kXfermode_NonDef);
+        mode = (SkXfermode::Mode)0;
+    }
     const uint8_t pad = 0;
-    writer.write32((nondef << 16) | ((unsigned)paint.getBlendMode() << 8) | pad);
+    writer.write32((nondef << 16) | ((unsigned)mode << 8) | pad);
 
     CHECK_WRITE_SCALAR(writer, nondef, paint, TextSize);
     CHECK_WRITE_SCALAR(writer, nondef, paint, TextScaleX);
@@ -171,6 +179,7 @@ static void write_paint(SkWriteBuffer& writer, const SkPaint& paint, unsigned us
 
     CHECK_WRITE_FLATTENABLE(writer, nondef, paint, PathEffect);
     CHECK_WRITE_FLATTENABLE(writer, nondef, paint, Shader);
+    CHECK_WRITE_FLATTENABLE(writer, nondef, paint, Xfermode);
     CHECK_WRITE_FLATTENABLE(writer, nondef, paint, MaskFilter);
     CHECK_WRITE_FLATTENABLE(writer, nondef, paint, ColorFilter);
     CHECK_WRITE_FLATTENABLE(writer, nondef, paint, Rasterizer);
diff --git a/src/pipe/SkPipeFormat.h b/src/pipe/SkPipeFormat.h
index 9a1d30c7be..8f5c8282e4 100644
--- a/src/pipe/SkPipeFormat.h
+++ b/src/pipe/SkPipeFormat.h
@@ -94,11 +94,12 @@ enum {
     kTypeface_NonDef    = 1 << 6,
     kPathEffect_NonDef  = 1 << 7,
     kShader_NonDef      = 1 << 8,
-    kMaskFilter_NonDef  = 1 << 9,
-    kColorFilter_NonDef = 1 << 10,
-    kRasterizer_NonDef  = 1 << 11,
-    kImageFilter_NonDef = 1 << 12,
-    kDrawLooper_NonDef  = 1 << 13,
+    kXfermode_NonDef    = 1 << 9,
+    kMaskFilter_NonDef  = 1 << 10,
+    kColorFilter_NonDef = 1 << 11,
+    kRasterizer_NonDef  = 1 << 12,
+    kImageFilter_NonDef = 1 << 13,
+    kDrawLooper_NonDef  = 1 << 14,
 };
 
 enum {
diff --git a/src/pipe/SkPipeReader.cpp b/src/pipe/SkPipeReader.cpp
index 47d4072d06..8840da1c83 100644
--- a/src/pipe/SkPipeReader.cpp
+++ b/src/pipe/SkPipeReader.cpp
@@ -149,13 +149,13 @@ static SkMatrix read_sparse_matrix(SkReadBuffer& reader, SkMatrix::TypeMask tm)
  *      pad zeros       : 8
  */
 static SkPaint read_paint(SkReadBuffer& reader) {
-    SkPaint paint;
-
     uint32_t packedFlags = reader.read32();
     uint32_t extra = reader.read32();
     unsigned nondef = extra >> 16;
-    paint.setBlendMode(SkBlendMode((extra >> 8) & 0xFF));
-    SkASSERT((extra & 0xFF) == 0);  // zero pad byte
+    SkXfermode::Mode mode = (SkXfermode::Mode)((extra >> 8) & 0xFF);
+    SkASSERT((extra & 0xFF) == 0);
+
+    SkPaint paint;
 
     packedFlags >>= 2;  // currently unused
     paint.setTextEncoding((SkPaint::TextEncoding)(packedFlags & 3));    packedFlags >>= 2;
@@ -180,12 +180,17 @@ static SkPaint read_paint(SkReadBuffer& reader) {
     CHECK_SET_FLATTENABLE(Typeface);
     CHECK_SET_FLATTENABLE(PathEffect);
     CHECK_SET_FLATTENABLE(Shader);
+    CHECK_SET_FLATTENABLE(Xfermode);
     CHECK_SET_FLATTENABLE(MaskFilter);
     CHECK_SET_FLATTENABLE(ColorFilter);
     CHECK_SET_FLATTENABLE(Rasterizer);
     CHECK_SET_FLATTENABLE(ImageFilter);
     CHECK_SET_FLATTENABLE(DrawLooper);
 
+    if (!(nondef & kXfermode_NonDef)) {
+        paint.setXfermodeMode(mode);
+    }
+
     return paint;
 }