[Offline Prefetch] Send GeneratePageBundleRequest to the server

components/offline_pages/core/prefetch/proto/any.proto

Index: components/offline_pages/core/prefetch/proto/any.proto
diff --git a/components/offline_pages/core/prefetch/proto/any.proto b/components/offline_pages/core/prefetch/proto/any.proto
new file mode 100644
index 0000000000000000000000000000000000000000..bc7100281f10f7f667b4f66d92fb229f1bdc82b9
--- /dev/null
+++ b/components/offline_pages/core/prefetch/proto/any.proto
@@ -0,0 +1,13 @@
+// Copyright 2017 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 = "proto3";
+option optimize_for = LITE_RUNTIME;
+
+package offline_pages.proto;
+
+message Any {
+  string type_url = 1;
+  bytes value = 2;
+}