Extract protobuf database into a new 'leveldb_proto' component

components/leveldb_proto/testing/proto/test.proto

Index: components/leveldb_proto/testing/proto/test.proto
diff --git a/components/leveldb_proto/testing/proto/test.proto b/components/leveldb_proto/testing/proto/test.proto
new file mode 100644
index 0000000000000000000000000000000000000000..84981051657158a9eb44ddcd5cd8b63556a1e97c
--- /dev/null
+++ b/components/leveldb_proto/testing/proto/test.proto
@@ -0,0 +1,20 @@
+// Copyright 2014 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.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+
+package leveldb_proto;
+
+// A proto to test leveldb_proto::ProtoDatabaseImpl.
+//
+// Next tag: 3
+message TestProto {
+  // Arbitary id.
+  optional string id = 1;
+
+  // Arbitrary data.
+  optional string data = 2;
+}