Add support for serializing/deserializing of SkDrawable

src/core/SkPicturePlayback.cpp

Index: src/core/SkPicturePlayback.cpp
diff --git a/src/core/SkPicturePlayback.cpp b/src/core/SkPicturePlayback.cpp
index f21ac32b961f0bcec6984951748b925e93e58189..f3bf62ca0bdf89315c2c4ed2f2205e0c14836b95 100644
--- a/src/core/SkPicturePlayback.cpp
+++ b/src/core/SkPicturePlayback.cpp
@@ -239,6 +239,15 @@ void SkPicturePlayback::handleOp(SkReader32* reader,
             (void)reader->skip(length);
             // skip handles padding the read out to a multiple of 4
         } break;
+        case DRAW_DRAWABLE:
+            canvas->drawDrawable(fPictureData->getDrawable(reader));
+            break;
+        case DRAW_DRAWABLE_MATRIX: {
+            SkMatrix matrix;
+            reader->readMatrix(&matrix);
+            SkDrawable* drawable = fPictureData->getDrawable(reader);
+            canvas->drawDrawable(drawable, &matrix);
+        } break;
         case DRAW_DRRECT: {
             const SkPaint& paint = *fPictureData->getPaint(reader);
             SkRRect outer, inner;