cc: Move SyncedScrollOffset to scroll tree

cc/proto/synced_property_conversions.cc

Index: cc/proto/synced_property_conversions.cc
diff --git a/cc/proto/synced_property_conversions.cc b/cc/proto/synced_property_conversions.cc
new file mode 100644
index 0000000000000000000000000000000000000000..09c8be2677731ae4b23d89b403f088285bb39afe
--- /dev/null
+++ b/cc/proto/synced_property_conversions.cc
@@ -0,0 +1,26 @@
+// 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.
+
+#include "cc/proto/synced_property_conversions.h"
+
+#include "cc/proto/gfx_conversions.h"
+#include "cc/proto/synced_property.pb.h"
+
+namespace cc {
+
+void SyncedScrollOffsetToProto(const SyncedScrollOffset& synced_scroll_offset,
+                               proto::SyncedProperty* proto) {
+  proto::ScrollOffsetGroup* data = proto->mutable_scroll_offset_group();
+  ScrollOffsetToProto(synced_scroll_offset.PendingBase(),
+                      data->mutable_pending_base());
+}
+
+void ProtoToSyncedScrollOffset(const proto::SyncedProperty& proto,
+                               SyncedScrollOffset* synced_scroll_offset) {
+  const proto::ScrollOffsetGroup& data = proto.scroll_offset_group();
+  synced_scroll_offset->PushFromMainThread(
+      ProtoToScrollOffset(data.pending_base()));
+}
+
+}  // namespace cc