Revert of Revert "Serialization of SkPictureImageFilter"

src/core/SkPicturePlayback.cpp

Index: src/core/SkPicturePlayback.cpp
diff --git a/src/core/SkPicturePlayback.cpp b/src/core/SkPicturePlayback.cpp
index e71a17fda51095ec44fa49d4e4aa6f81b2493b0b..8b8c6b0862dad7bb6d0bc643de3b09b0abca4fd7 100644
--- a/src/core/SkPicturePlayback.cpp
+++ b/src/core/SkPicturePlayback.cpp
@@ -431,6 +431,22 @@
     stream->write32(PICT_EOF_TAG);
 }
 
+void SkPicturePlayback::flatten(SkWriteBuffer& buffer) const {
+    writeTagSize(buffer, PICT_READER_TAG, fOpData->size());
+    buffer.writeByteArray(fOpData->bytes(), fOpData->size());
+
+    if (fPictureCount > 0) {
+        writeTagSize(buffer, PICT_PICTURE_TAG, fPictureCount);
+        for (int i = 0; i < fPictureCount; i++) {
+            fPictureRefs[i]->flatten(buffer);
+        }
+    }
+
+    // Write this picture playback's data into a writebuffer
+    this->flattenToBuffer(buffer);
+    buffer.write32(PICT_EOF_TAG);
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 /**
@@ -593,6 +609,15 @@
     return playback.detach();
 }
 
+SkPicturePlayback* SkPicturePlayback::CreateFromBuffer(SkReadBuffer& buffer) {
+    SkAutoTDelete<SkPicturePlayback> playback(SkNEW(SkPicturePlayback));
+
+    if (!playback->parseBuffer(buffer)) {
+        return NULL;
+    }
+    return playback.detach();
+}
+
 bool SkPicturePlayback::parseStream(SkStream* stream, const SkPictInfo& info,
                                     SkPicture::InstallPixelRefProc proc) {
     for (;;) {
@@ -603,6 +628,21 @@
 
         uint32_t size = stream->readU32();
         if (!this->parseStreamTag(stream, info, tag, size, proc)) {
+            return false; // we're invalid
+        }
+    }
+    return true;
+}
+
+bool SkPicturePlayback::parseBuffer(SkReadBuffer& buffer) {
+    for (;;) {
+        uint32_t tag = buffer.readUInt();
+        if (PICT_EOF_TAG == tag) {
+            break;
+        }
+
+        uint32_t size = buffer.readUInt();
+        if (!this->parseBufferTag(buffer, tag, size)) {
             return false; // we're invalid
         }
     }