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

src/core/SkRecordOpts.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkRecordOpts.h"
 
 #include "SkRecordPattern.h"
@@ skipping 80 matching lines @@
                                               bool isSaveLayer,
                                               SkPaint* paint) {
     // We assume layerPaint is always from a saveLayer.  If isSaveLayer is
     // true, we assume paint is too.
 
     // The alpha folding can proceed if the filter layer paint does not have properties which cause
     // the resulting filter layer to be "blended" in complex ways to the parent layer. For example,
     // looper drawing unmodulated filter layer twice and then modulating the result produces
     // different image to drawing modulated filter layer twice.
     // TODO: most likely the looper and only some xfer modes are the hard constraints
-    if (paint->getXfermode() || paint->getLooper()) {
+    if (!paint->isSrcOver() || paint->getLooper()) {
         return false;
     }
 
     if (!isSaveLayer && paint->getImageFilter()) {
         // For normal draws, the paint color is used as one input for the color for the draw. Image
         // filter will operate on the result, and thus we can not change the input.
         // For layer saves, the image filter is applied to the layer contents. The layer is then
         // modulated with the paint color, so it's fine to proceed with the fold for saveLayer
         // paints with image filters.
         return false;
@@ skipping 10 matching lines @@
     }
 
     if (layerPaint) {
         const uint32_t layerColor = layerPaint->getColor();
         // The layer paint color must have only alpha component.
         if (SK_ColorTRANSPARENT != SkColorSetA(layerColor, SK_AlphaTRANSPARENT)) {
             return false;
         }
 
         // The layer paint can not have any effects.
-        if (layerPaint->getPathEffect() ||
+        if (layerPaint->getPathEffect()  ||
             layerPaint->getShader()      ||
-            layerPaint->getXfermode()    ||
+            !layerPaint->isSrcOver()     ||
             layerPaint->getMaskFilter()  ||
             layerPaint->getColorFilter() ||
             layerPaint->getRasterizer()  ||
             layerPaint->getLooper()      ||
             layerPaint->getImageFilter()) {
             return false;
         }
         paint->setAlpha(SkMulDiv255Round(paint->getAlpha(), SkColorGetA(layerColor)));
     }
 
@@ skipping 22 matching lines @@
 };
 void SkRecordNoopSaveRestores(SkRecord* record) {
     SaveOnlyDrawsRestoreNooper onlyDraws;
     SaveNoDrawsRestoreNooper noDraws;
 
     // Run until they stop changing things.
     while (apply(&onlyDraws, record) || apply(&noDraws, record));
 }
 
 static bool effectively_srcover(const SkPaint* paint) {
-    if (!paint) {
-        return true;
-    }
-    SkXfermode* mode = paint->getXfermode();
-    if (SkXfermode::IsMode(mode, SkXfermode::kSrcOver_Mode)) {
+    if (!paint || paint->isSrcOver()) {
         return true;
     }
     // src-mode with opaque and no effects (which might change opaqueness) is ok too.
     return !paint->getShader() && !paint->getColorFilter() && !paint->getImageFilter() &&
-           0xFF == paint->getAlpha() && SkXfermode::IsMode(mode, SkXfermode::kSrc_Mode);
+           0xFF == paint->getAlpha() && paint->getBlendMode() == SkBlendMode::kSrc;
 }
 
 // For some SaveLayer-[drawing command]-Restore patterns, merge the SaveLayer's alpha into the
 // draw, and no-op the SaveLayer and Restore.
 struct SaveLayerDrawRestoreNooper {
     typedef Pattern<Is<SaveLayer>, IsDraw, Is<Restore>> Match;
 
     bool onMatch(SkRecord* record, Match* match, int begin, int end) {
         if (match->first<SaveLayer>()->backdrop) {
             // can't throw away the layer if we have a backdrop
@@ skipping 107 matching lines @@
 }
 
 void SkRecordOptimize2(SkRecord* record) {
     multiple_set_matrices(record);
     SkRecordNoopSaveRestores(record);
     SkRecordNoopSaveLayerDrawRestores(record);
     SkRecordMergeSvgOpacityAndFilterLayers(record);
 
     record->defrag();
 }