[blimp] Add SkPicture caching support.

cc/blimp/picture_data_conversions.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CC_BLIMP_PICTURE_DATA_CONVERSIONS_H_
+#define CC_BLIMP_PICTURE_DATA_CONVERSIONS_H_
+
+#include <memory>
+#include <vector>
+
+#include "cc/base/cc_export.h"
+#include "cc/blimp/picture_data.h"
+
+namespace cc {
+
+namespace proto {
+class SkPictures;
+
+CC_EXPORT void PictureDataVectorToSkPicturesProto(
+    const std::vector<PictureData>& cache_update,
+    SkPictures* proto_pictures);
+
+CC_EXPORT std::vector<PictureData> SkPicturesProtoToPictureDataVector(
+    const SkPictures& proto_pictures);
+
+}  // namespace proto
+}  // namespace cc
+
+#endif  // CC_BLIMP_PICTURE_DATA_CONVERSIONS_H_