Effects on the paint also prevent layer merge optimization.

src/core/SkPictureRecord.cpp

Index: src/core/SkPictureRecord.cpp
diff --git a/src/core/SkPictureRecord.cpp b/src/core/SkPictureRecord.cpp
index 4a5aff2d722d7a66c66eac6a75a1ec20cbf52bef..36b0763e9ff128bb3adb7acd9b345b5bf0e3749f 100644
--- a/src/core/SkPictureRecord.cpp
+++ b/src/core/SkPictureRecord.cpp
@@ -427,7 +427,7 @@ static bool merge_savelayer_paint_into_drawbitmp(SkWriter32* writer,
     SkColor layerColor = saveLayerPaint->getColor() | 0xFF000000; // force opaque
 
     SkAutoTDelete<SkPaint> dbmPaint(paintDict->unflatten(dbmPaintId));
-    if (NULL == dbmPaint.get() || dbmPaint->getColor() != layerColor) {
+    if (NULL == dbmPaint.get() || dbmPaint->getColor() != layerColor || !is_simple(*dbmPaint)) {
         return false;
     }